Hapy Turns 50

Quick post to commemorate Hapy the wonderbus turning 50 years old. Totally unrelated, but a fascinating video, here is a company in the UK looking at building an internal combustion engine that runs on hydrogen. Cool stuff. On to the celebration...

How 50?

I guess we start where I did with every person who asked "how do you know his exact birthdate?". I refer you to this post where I deciphered the manufacturing codes aka M-codes. Basically, every VW of this vintage has the planned manufacturing date imprinted on the plate. So, based on week number and day number, you can determine your vehicle's manufacturing date. Hapy has been in the family for less than half of his life, though.

When I received him, his engine had been replaced, but the interior, exterior, wiring, and everything else was 100% original. Consider "original" does not always mean "good". There was mold in the upholstery, the seats were shot, the pop-top bellows were dry-rotten and torn. But, I made use of him, in his original condition, even trying to return many of the systems to spec. Ultimately, though, safety concerns for my then-young kids started me down the trail I have documented here.

First, it was the sink/icebox unit blocking the handle to the sliding door. I considered the "what if" of getting into an accident that renders me unconscious while my kids are trapped in the back, unable to open the slider because their arm's aren't long enough to reach around the sink. So, that got pulled, and down the rabbit hole I went.

Park Play

To celebrate Hapy, and honestly any excuse to celebrate this year is a fairly good one, we reserved 5 camping spots in nearby LL Stub Stewart State Park. Our long time friends GratefulEd, lovely wife Dawn, and Belle joined us, as did my brother Eric, who rented a Eurovan from Road Trip Oregon for the special occasion with his 2 daughters (K4 and K5). Many other friends and family were on-hand on Saturday for the big party and many of them stayed overnight. We also had arranged a duo to play some jazz and old country in one of the reserved campsites in the center of the reserved spots. Unfortunately, the park rangers shut the duo down before they completed the jazz portion of their set. So, they completed their performance sans-amplification. Undeterred, Boo rolled out a stack of subs, a couple of coolers of bev's and a couple trays of VW-emblazoned cupcakes for a singing of Hapy Birthday. Yes, yes we did.

One of our gests had set up cornhole, another had set up badminton and Eric set up croquet. So, we played yard games while the acoustic duo played. It was the hottest day of the weekend, so impromptu shade was set up. When the official music completed, many of the day-trippers, and our official musicians, headed home. Those who remained shifted from the "venue" campsite to Hapy's front door for some (also mostly acoustic) jamming. For this, we were joined by friends from the Hillsboro bluegrass scene (some pictured, some not). We played until we were shut down by the park rangers again (silence expected at 10:PM), but not before our neighbors had joined us, demonstrating again that we all need a little more joy, and few things bring joy like live music and a small crowd laughing. After we stopped playing, we continued to visit (read: drink) for a while, and we broke up by midnight.

Everyone other than Boo, Hapy and me left the next day. Boo had rented some electric-assist bikes so we took a ride that afternoon after everyone left. There is a paved trail from Manning to Vernonia that passes right through the state park, and we explored a small section of it. That evening, we gazed at the stars through a borrowed telescope. With the lack of white noise from the city lights and no visible moon, there are just so many stars to see. We pointed the telescope first at single noticeable stars, but found it much more interesting to point it at a relatively uninteresting area of space and then see how many stars appeared. We both caught a shooting star through the lens that way, while also noting that in an otherwise uninteresting area of space there are still hundreds of stars visible through a non-commercial tri-pod'd telescope.

There and Back

No trip in Hapy is complete without a review of how well the bus handled. The drive out was late afternoon on a Thursday. Traffic wanted to go faster than Hapy did. Hapy still did well, driving into an on-angle headwind. The handling was much better after the shock-absorber adjustment, though the increased speed and headwind caused his engine temps to run a little high (topped at 198*F). We did not experience meaningful engine stumbling in either direction, nor did we throw a code. So, I think that much of the stumble was some bad fuel or a partially clogged clean filter (which I replaced after 4Peaks) or both. I will still be looking into other causes. The trip back was even better than the drive out. Whatever wind there was, it must have been at least partially behind us. Hapy's temperature rarely ticked above 186*F, and he was happily cruising at 55-60mph*. I had the stereo blasting an old Jerry Garcia Band bootleg, my elbow resting on the open window, and we just cruised with one hand on the wheel. The merge from 47 onto US26 was effortless with the bigger nozzles and chipped computer allowing Hapy to scoot into traffic. Honestly, it was the easiest drive home I can remember.

*: I use the asterisk here because Boo was following in a chase car, and was able to tell me just how fast I was going when... and when Hapy's speedo says "50" I am going 55. When his speedo says "55", I am going 62. So, the speedo is definitely at least 10% off, showing 10% slower than I really am. This is consistent with the odometer checks I have done along the freeway, showing the odometer is closer to .8 of a mile when the mile marker says a full mile. Since my mpg has been getting calculated without this extra math, the mpg is even more impressive. I have been getting just shy of 30mpg with the odometer reading at least 10% low. So, I'm really getting 33mpg or better.... in a bus that's loaded for camping 95% of the time.

That's it for today. Thanks, as always, for following along.

Throw-back to embedded picture captions like I used to do:

top - meadow between the Dairy Creek campgrounds

next from top - (L-to-R) Stevan on Mandolin, Rose (standing) on fiddle, Rodney (back turned) on guitar, Joe (standing) on guitar, Dawn (seated can only see top of her head/hat), Mo (standing), me (back turned) on bass, Ed (back turned) on guitar. Joey (mostly obscured by Ed)

next from bottom - Ed and Belle in full-fest-form

bottom - Boo on the bike trail

And, here are some other pictures:

(L-to-R) Rose, Boo, Joe, Mo
and me (back-turned)

Boo and I sharing
the lot couch

LL Stub Stewart camping

(L-to-R) Rodney, Stevan, Joey,
Joe, Boo (back turned),
Mo (obscured) and
me (back turned)

Oh, Nemo

Today's post covers my challenges with Nemo's electrical and computer system simply trying to get him to start, or maybe a signal on the OBD-2 port. The car-work hours that I did not want to spend sanding on Zed, I spent doing this... until this took over. Yeah, I know. I could use another hobby.

No Start

Like so many issues with these old cars, our challenges with Nemo started with him not starting. His battery had been sitting on a trickle charger all winter, but I had left his hood cracked to make room for the alligator clips, so this ultimately was self-inflicted. Love those. But, the path we took to get there was interesting. Nemo is sitting under the fabric carport blocking a garage door. Behind that garage door sits Oliver, the 1978 MGB convertible, that I would very much like to be road testing and otherwise driving around. So, enter my motivation for moving Nemo. Insert key, turn ignition to "RUN". I see some familiar idiot lights, including the battery, oil and check-engine. Turn to "START" and he rev'd but would not start. I went around to the tailpipe and could not smell gas, so I start with the assumption that it is fuel delivery.

Before I did anything else, I considered what I experienced when I turned the key to "RUN". I did not hear the fuel pump cycle. I did not hear the radiator fans kick on. So, something is not getting the "RUN" signal. So, I pull out the UltraGauge and plug it into the OBD-2 port. I get a never-ending "scanning..." message. Well, that's not good. I double-checked the UltraGauge in Hapy, and the computer linked within a few seconds. Okay, we have trouble with Nemo's diagnostic system which could prevent a start or we have multiple things going on. With this car, the latter is probably true. First, I tried to isolate the OBD-2 issue, and kill many many hours doing so.

OBD-2 Issue Diagnosis: General

The early B5 versions of the A4 had some interesting 1 or 2 year only issues. One of the oddities around 1997, when Nemo was sold, was the engineers choice to integrate the stock stereo with the "K-line": the signal processing wiring between the computer, many components and the OBD-2 plug. In these late 90's cars, it is the K-line you are subscribing to, not the more modern "CAN BUS". Okay, cool. There are many modules plugged into the K-line, but they are all in parallel. the diagnosis theory goes that when you get no signal on the K-line it is because one of the modules is faulting out, grounding the K-line. Once you can identify and remove the faulty module, you will get a signal on the K-line. You will probably get a failure code for that module, but you will at least get a signal. So, away we go, trying to figure out what modules are even on the K-line, and then isolating them.

OBD-2 Issue Diagnosis: Radio

The stock radio wiring was unceremoniously cut to pieces by the idiots at Car Toys when they installed an aftermarket stereo. Based on the wiring diagrams I have found and the commentary on the interwebs, I am not sure this car actually had that K-line-in-the-stereo thing. I did check the wires for the right color combinations, and for wires that were the correct colors for the K-line. I was unable to find them. There are, however, many wires sticking out of the hole where the radio used to be... before it was ripped off in Eugene. I intend to re-integrate an original plug before I put all this back together, but that's another day. I moved on to the next possible culprit: the climate control system.

OBD-2 Issue Diagnosis: Climate Control

found in climate
computer

The climate control system in these cars is another little computer. In some models, it is held in place with a couple brass clips. In Nemo, I had to remove the center console cover plate / face and found 2 Phillips screws holding it in. Once threaded out, the unit removes through the front. I unplugged the unit and checked the OBD-2 for a signal. Nope. I did, however, find a soda/beer can pull tab inside it (picture on the right, here, laying on the carpet after I removed it from inside the climate control computer thing). So, that was interesting. Next.

OBD-2 Issue Diagnosis: ABS (Brakes)

The fine folks on the interwebs have found that the ABS sometimes causes K-Line problems. The way to identify if it is the problem is to disconnect the plug. The ABS unit is on the driver (left) side, next to the washer bottle. You simply pull up on the silver metal tab and the plug lifts out of the socket. I found a piece of electrical tape floating around in there. Another question-mark from the prior owner. Neat. I checked the OBD-2 for a signal. Nope. I shot the socket and the plug with DeOxit and left it disconnected for the rest of my tests. I figured I might as well leave it better than it was (DeOxit, not leaving it unplugged). Next!

OBD-2 Issue Diagnosis: Dash Cluster

Moving on, we consider the dash cluster. The entire thing is held in by 2 Torx-head screws from the front, hidden behind a cover plate just above the steering wheel. Pull the cover plate, remove the screws and it pops right out. I unplugged the various cable plugs and checked the OBD-2 again. Nope. Grr... Next!!

OBD-2 Issue Diagnosis: ECU

example A4 ECU 

It seems like every system on the engine that has more than one wire into it delivers some signal to the computer. So, this seemed like the next logical step. I figured if I could get a signal after unplugging the small plug on the ECU, I would have shown that the issue is in the engine compartment and I could put everything in the cabin back together again. If the issue remains, then it could be the ECU. So, I disconnected the small plug from the ECU and we still didn't have a K-line signal. Grr...

So, I plugged the ECU, ABS and the dash cluster back in, turned the key to RUN and heard the click-snap of some relays firing, but no fuel pump nor fan spin. I could not remember if I heard the relays before, but this changed my thinking. If at least some of the relays are firing, then the ECU is telling them to. If there is a Check Engine Light, then the ECU must be at least partially working. Perhaps the K-line / OBD-2 issue is completely unrelated and this is just a simple fuel supply issue. So.. new plan: get the fuel pump to fire.

Fuel Pump Test

As is so often the case in laboratory settings, the pre-work for the experiment is where all the time is taken. Such is the case here. I started by removing the plate covering the fuel pump. This sits behind the rear seat in the trunk on the passenger (right) side, and is held in place with 3 very short Phillips screws. Once the plate is removed, you can see the top of the fuel pump. There are 2 fuel lines, one supply and one return, and a single electric plug. I found that slightly wiggling the plug allowed it to pull off the pump. YMMV. Once removed, you will see 4 pins. 2 of them are for the fuel level and 2 are for the pump. I started my tests with basic resistance and continuity-to-ground. Things seemed fine, so I shifted focus to test-firing the pump by applying 12V to the pump.

This is where the experiment set up took some time relative to the actual test execution. I ran a pair of wires from near the battery (not hooked up) back to the fuel pump. At the battery, I taped 10A fuse to the "red" wire and alligator-clipped the other side of the blade to the positive battery post. I alligator-clipped the "black" wire to the negative post. Back at the fuel pump, I applied the red and black wires to the fuel pump and it fired right up. I held the wires there a few second to demonstrate that it would not just run for a second and die. So, we have a good pump, but the pump won't fire from a relay signal. So, next we check the voltage from the relay, after we put the experiment wiring away.

Fuel Pump Relay Test

A4 Fuel Pump Relay

Back up front, I took a red wire, stuck it into the voltage-supply pin in the wiring plug at the fuel pump and tossed the other end through the cabin, over the outer edge of the driver seat. My plan was to compare the voltage sent to the pump at the pump. Since the relay only pops for a second when you turn on the ignition, I had to have my test equipment near the ignition key. I stuck my black lead against the metal fuse box mount, held the red lead against the wire I tossed through and turned the ignition to "RUN". I got 5V. I checked other spots around the fuse box and got 13V, so I started thinking that the relay was bad, dropping the voltage from 12/13V to 5V which, of course, is not enough to run the pump. So, I swapped out the relay... and the fuel pump still would not run. Great. I concluded that the 5V I read was actually the base charge for the fuel level sender and not the supply for running the pump. 

So, I checked the voltage at the supply-side of the relay: 13V. I jumpered across the relay pins, and the pump fired up. So, we're back to the ECU is not sending a signal. Fearing it is the ECU, I went looking for any other reason. I recalled that when Dot (the white 2000 VW Jetta 2.0 which broke the timing belt) failed, one of the theories for not starting was a crank position sensor. The thinking is that if the ECU doesn't know where in the revolution the crank is, it doesn't know when to fire, so it doesn't try. It is not as clear whether a failing crank sensor would prevent the fuel pump relay from getting a signal from the ECU, however. As much as I have tried to avoid it, it felt like I was sliding into just-swap-parts problem solving. At $35US for the least expensive part-to-swap (crank position sensors start closer to $60US), this can get needlessly expensive very quickly.

Crank Position Sensor (CKP)

A4 Crank Position Sensor

I have mentioned before my belief that the Audi engineers are sadists. Only someone who takes pleasure in other's pain could arrange for replacement items to be so hard to get to. Case-in-point: the crank position sensor. The crank runs the length of the block (obviously), so given a blank canvas, an engineer could potentially place a sensor anywhere along that axis. Chosen location? Directly under/behind the oil filter so you either have to remove the oil filter (forcing an oil change, which arguably is due) OR you need to perform contortions to get an Allen-head wrench in there. If you go this route, consider that the further the bolt comes out, the closer you get to the oil filter. At least there is only one fastener. These sensors have a long lead on them that plugs into the engine harness... behind the coolant bottle. In Nemo's case, this plug was fairly easy to get to. There are methods for testing the sensor, of course.

The Audi/VW sensor has 3 wires, from pin 1-3: power | signal | ground where the power and signal connect to the ECU and the ground finds its way to the chassis. To test, 12V and ground need to be supplied to the sensor plug (once disconnected from the harness) and a multimeter checking the signal wire for an AC wave signal while the engine is turning. No signal = bad sensor. Since no local shops had a CKP, I returned to sanding Bondo in Zed while I waited for the part to arrive.

Once I had the part in hand, I checked the resistance between the pins. I got 500ohms +/- between the middle pin and one of the outer pins. Using that as a baseline, I swapped out the CKP and then tested the one I had just removed. Same resistance. So, I concluded there was nothing wrong with the old one and put it in the stash of A4 spare parts (with the fuel pump relay).

ECU Swap

At this point, I had run completely out of ideas fo4r why the ECU was not sending a "go" signal to the fuel pump relay. I hit the local junkyard looking for a just-dropped-off A4 to scavenge the ECU. None of the A4's there had the right ECU, but I did get an ECU box cover: Nemo's had a good-sized hole in it where I thought water might have entered. Without another option, I hit eBarf and found an ECU with the same part number as the one as was currently in Nemo at a salvage yard on the East Coast (with a 30 day return policy!). Hopeful, I swapped out the ECU's which consisted of pulling out the big plugs in the back of the old and plugging them into the new one, since the box was still lid-less. I had some concern that energizing the ECU could fry it if the underlying condition still existed.

Still, I turned the key to "RUN" anyway... and heard the radiator fans and fuel pump cycle for a second before shutting off. This was how things used to work. So, I turned to start and he fired right up. I have concluded that my first guess was the correct one: I had left the hood open a little bit to make room for the alligator clips on the trickle charger, and with the hole in the ECU box lid, water got into the ECU and partly fried it. If I had not had the experience with the chipped ECU for Hapy when the computer semi-worked, I would not have been so quick to accept this. The Check Engine Light lit, so the A4 chat-boards all assume that means the ECU is fine. NOT TRUE. It could be partly damaged, like Nemo's.

The climate control is still in pieces, the lower dash panel is off, and the radio wiring, well, it's the same as it was: a mess. While I can move Nemo out of the way so Oliver can go for a spin, Nemo is not ready for driving around just yet. The re-assembly will wait, and I'll probably post on at least the re-wiring of the stereo plugs that the idiots at CarToys cut apart. I did, however, install the ECU box lid, complete with threading in the screws to hold it tightly shut. No more water getting in there.

Thanks, as always, for following along-

Malone Tuning Stage 2

Today, I wrap up the saga of the bigger injector nozzles and the Malone Tune in the VW bus. And, finally take Hapy for a drive. But first, for my mj-friendly readers, Hapy 420; celebrate safely :) Before I get flamed, yes, I know 420 did not stem from a date. It came from a time-of-day, but that does not change the fact that people celebrate pot on the 20th of April. It does, however, explain why some folks celebrate 4:20 in the afternoon with their personal favorite intoxicant.

Also, please note that the fine people at blogger have notified their users that "After July 2021, your feed will still continue to work, but the automated emails to your subscribers will no longer be supported." So, if you are relying upon an email to let you know that there is a new post on one of your favorite blogs, this will no longer function starting in August.

On to chipping Hapy's TDI computer...

Malone Tuning

In the TDI world, and increasingly outside of it, Malone Tuning is kind of the hallmark for getting your ECU "chipped". For those who wish to get more out of their engine, there is a tune for practically any set up and performance target. Malone has a few tunes below the "stage 2" that I selected, which either maximize power with a completely stock set up or adjust settings for best economy. I decided that I wanted larger injectors so I could get a little more oomph, so the stage 2 is the better choice. I do not have any plans to upsize my turbo, but if I did, this tune would support it.

On the turbo, I am running a stock VNT-15. The easiest upgrade would be to find and install a VNT-17. These appear on some cars stock. The advantage of the 17 is that it can create more boost (in pounds per square inch or PSI), because everything is bigger. The downside is the turbo lag (delay in the arrival of the power) is increased, moving the powerband up the RPM's. Since the sound and vibration of the bus increases with the RPM as well, I generally try to stay below 3500RPM. The VNT-15 turbo starts to kick in around 1800, but isn't really all-there until closer to 2200. So, right now, my total band for power is around 1300RPM (2200-3500). Adding a bigger turbo will reduce that or push my top-end higher to compensate which would make for a more noisy / shaking experience. It is for this reason that I am not really considering a turbo swap. The $1000US for a turbo is, of course, a factor too. Besides, we haven't seen how bigger nozzles and a tune will affect things yet!

Ship Ship Ship Ship

projected HP and torque
increases from stage 2

The actual purchasing of a Malone tune is through "Tunezilla". For someone with a super-early TDI like mine, it is not a simple download of software, though. A pair of chips need to be swapped out. This can be done by their shop, who does this every day, or they will send you the chips to do it yourself. I decided to have them do it, and sent my ECU off to them. Less than a week later, it was back in my hands, having traveled through customs twice (Malone is in BC, Canada) and their shop. Unfortunately, FedEx international shipping was a little rough with the package and after some highly responsive tech support from Malone to diagnose, I had to send it back. Malone determined that a handful of the solder joints broke free during shipping, causing the ECU to not power up.

The symptoms were consistent: apply switched 12V power and nothing happened. No messages on the "K" line thru the OBD-II plug to my little reader, no check engine light, no glow-plug light, but there was power at and past relay 109. So, there was some power moving through the ECU (relay 109 is triggered by the ECU), just not all of it.

I sent it back and they turned it around in 2 days, finding and fixing the loose soldier joints. They super-packed it with extra puff, so we would not have a solder fail repeat. Again, about a week after I sent it to them, it was back in my hands. An aside: when I sent it the first time, FedEx said they were not delivering to that address, so I went through UPS. UPS cost twice as much. The second time I sent it, FedEx was delivering there again. So weird.

Holy Head Snap

Hapy says "lets play"

Anyway, this time when I plugged it in, I had an entirely different experience. I turned the key to "RUN" and heard the familiar "snap snap" of the relays and the dash-pod waking up. I turned the key to start and Hapy fired up immediately (bum-bum broom). He rough idled for a few seconds and then settled down at 900RPM. I cleared the codes (per Malone instructions) and then played with the go pedal. Oh, this is gonna be fun. The new injectors don't leak at all, and the pump retains prime after being left idle for days. Bigger nozzles, stage 2 tune, wrapped exhaust, oil temp and pressure gauging, fresh wiring from front to back, including a new, custom fuse/relay box, the fat-plug harness surgery... All I needed was a test drive and Hapy could be ready to rumble.

Not so fast. It would be irresponsible to put that much new power on the road without verifying the brakes. So, before I got my "go" on, I adjusted the rear drum brakes, checked the lining on the front and confirmed I had full fluid. I switched out the system to DOT4 a couple of years ago, so the fact that he has been sitting most of the time since did not concern me as much as DOT3 would have. DOT3 absorbs moisture (bad for your fluid life) over time while DOT4 does not.

dyno curve compare
stock -v- stage 2

So.. with brakes adjusted, and all the stuff I said a paragraph ago now complete, I'm ready to test drive. We have been blessed with pleasant (20*C / upper 60*'s F) high temperatures so far this April, with many sunny skies. This makes for some perfect conditions for a test drive. While I only did the usual lap for my test, it was amazing. Somewhere along the way when I worked on the original bus dash I failed to re-connect the speedometer cable, but otherwise, everything worked very well and the brakes responded strong. As I turned onto the main road, I quickly moved through 1st and 2nd gear. When I put it in third, I really put my foot into it. I didn't floor it, but I put it pressed it pretty far down. The turbo spun up and I lost traction in my drive tires: I was burning rubber in 3rd gear, rolling at around 25mph. That'll do. Hahaha. I don't think I'll need to do anything more performance-wise, though I may replace the exhaust pipe if that will reduce exhaust gas temperature (EGT) or if the wrap destroys it. When I got back home, I felt the rear tires; they were warm, but not hot. Same goes for the rear drums. Then, I checked the wrapped exhaust which was also warm, but easily touchable.

With a consistent accelerator pedal (no more 1200 limp mode) and better visibility into the engine health, Hapy is pretty much ready for some road-tripping this Summer. Now that CoViD-19 vaccines are becoming more widespread and plentiful, Hapy's system-ready status could not arrive soon enough.

That's it for now. As I go, another reminder that Hapy turns 50 on 3-September-2021 and we will be celebrating it at LL Stub State Park. If you have nothing else to do Labor Day weekend, there are some great hiking, horse and bike trails there as well as our little birthday.

Thanks, as always, for following along--

P0121 - the 1200 rpm limp mode - Final

Today I complete the saga of trying to resolve the P0121 error that persisted after I re-wired the front-to-back cable, the fuse box (main donor) harness and the fuse box / relay box. It is terribly ironic that this post arrives on Groundhogs Day. I have had drive-by-wire (P0121) issues so much since I did this conversion, it was like my own personal Groundhogs Day every time I dropped into that 1200 rpm zone. Queue the Sonny and Cher song. With only one error code, you would think this would have been easy. Nope. At least, after all the wiring changes, I only had the one code.

Pedal Pedal

new on bottom

When I left off my last post, I had concluded that the wiring was not the issue, and ordered a replacement pedal. These aren't cheap, but I found one for around $100US (which was a really good price). It took a while to get here from the east coast, but once in-hand, I thought it would be interesting to compare the new and the old. Physically, they are very similar, but the old one has a removable panel. I pulled out the multi-meter and started testing the resistance between all of the pins on both pedals. This was illuminating.

Then, I popped each pedal into a bench vice so I could depress the pedal by tightening the vice. This allowed me to measure how the resistance changed across the pins as the pedal was depressed. Generally, both pedals demonstrated the same direction of resistance change relative to the direction of the pedal movement, but there were some definite differences. For example, the resting resistance between the pins (which had a corresponding resistance on the other pedal) was lower on the old pedal than the new one. I was able to correct for most of the difference by shifting the little cover on the old pedal forward (front-is-front / away from the footpad). Prior to moving the cover, it was near the mid-point of the front-to-back adjustability.

The biggest difference I found was that on the new pedal, there was infinite resistance between pins 2 and 4 when the pedal was 0% depressed. The old pedal, however, had a measurable resistance (1760 on the second-to-highest sensitivity). Once the new pedal moved even a little off of 0% depressed, resistance was measurable. I thought this was the big tell that the old pedal was the cause, but before I get into the in-situ test, here are some tables and notes around my testing of the 2 pedals. I suspect there will be readers who are only here for that.

Testing Static Resistance between Pins 

inside the removable
cover

In the table below, the multi-meter was set at the second-to-most sensitive resistance measuring. The number on the top is from the new pedal, and the number below it is from the old one before I tweaked the little cover position. 

The word "flash" means that even though I tested these pin resistances 5 or 6 times, on the new pedal, the resistance between these pins would flash a quick 4-digit number and then go to infinity. I tried to measure it with different settings on the multi-meter, but for my purposes, it was clearly very different from the "old" pedal. Since it happened every time, I concluded it was not caused by my probe accidentally touching pin 3 while approaching pin 4. I did experience intermittent issues with my cheap $5US Harbor Freight multi-meter where the whole plastic probe would fall off the lead. The multiple tests ruled that out as a cause for the "flash" as well.

The "fix" for the probe-fall-off: Strip back a little bit extra off the end of the probe wire and push it back into the probe. Check continuity between the probes. Down to 0 or nearly 0? Perfect. Hold the wire and probe steady and tape the wire to the probe, and then run more tape up the wire a couple of inches. That wire won't pop out easily again.

Where were we? Oh, yeah.. while there are 6 pins, there was not a measurable resistance between most of them. That is why some pins are not on the tables at all and some pin intersections have a blank square. In both cases, there was no measurable resistance. Pin 1, for example, had no measurable resistance to any other pin. Neat, eh?

	3	4	6
2	1320 900	flash 1760
3		1010 996
5			1070 945

 

Testing Transient Resistance between Pins

Next, let's look at the throttle testing in the vice. So, consider these values as "when the pedal is depressed, the resistance between the pins..."

hunting gremlin

	3	4	6
2	unchanged unchanged	*drops (1590, 1480) drops (1570)
3		rises (1422, 1700) rises (1300)
5			infinite infinite

The * is to show that the resistance between the pins suddenly changes from infinite to something (high) 4-digit measurable once the pedal is starting to get depressed. The resistance between pins 5 and 6 goes to infinite as soon as the pedal starts being depressed. This is all really cool stuff, but are we closer to having an accelerator pedal again? Well, I plugged the 6-pin flat-connector into new pedal and started the engine. Idle... and then 1200 rpm mode. So, nope. So, next I checked the voltage of the 6 pins on the flat connector, and put my findings in another table below. Perhaps this would have been a good thing to test while waiting for the pedal to arrive. Or better yet checking before ordering one. Hindsight is great.

Voltage at the Flat Connector

The "should be" column is from comment #7 on this posting on the TDIClub. Fred's TDIClub is such a fantastic resource. Highly recommend for the knowledge, and they are generally nice folks too, unlike some other boards where so many replies to questions are "use the search function". Helping not helping.

	should be	no key	key to run
1	0-90%: 9+V	no V not ground	..8V
2	5v	no V not ground	5V
3	ground	ground	ground
4	.35V -> 4.5V	no V not ground	2.7V
5	0%: 0V >0%: 2.758V	no V not ground	8V
6	ground	ground	ground

So, I looked at this table and some of the values look spot-on, like the 5V reference voltage on pin 2 and the grounds on 3 and 6. The other 3 look like I wired them incorrectly. Like, maybe wire 5 should be going to pin 1, wire 1 to pin 4 and wire 4 to pin 5. At least then the voltages would be in the right ballpark. So, before I assume that my ECU is fried (the only other reason I can come up with for this), I decided to change some of the wiring to reflect this re-arrange first. Considering the difficulty I had determining the logic at the blue T10 I mentioned in the last post, this felt very much like a real possible cause.

Change 3 Wires

more hunting gremlin

Since the wiring on the fuse-box / relay-box harness was very hard to get to, and the 6-pin flat-connector is very easy to get to, I decided to change the wiring at the 6-pin flat-connector. This will force an update to my wiring diagram, but this was the fastest route to testing the theory while minimizing the potential "bump risk" (you bump something and now you have a whole new set of problems). Anyway, this re-wire was very easy: label the 3 wires, cut the heat-shrink, unwire, re-wire, re-heat-shrink.

Of course, any final test couldn't be without it's own challenges, as the electrical acted batty for about a day while I chased gremlins again. Something was creating a vibe, making the system act like the battery was dead. For example, the hazard switch would cause the relay to buzz, lights wouldn't come on, etc but a voltage test on the battery was fine. After several hours of tearing the dash board apart, believing I had bumped something when doing the flat-connector, I removed the battery from the bus and verified it had over 13.5V (full charge). So, I put the battery on the bumper and hooked up the battery cables, omitting the float charger, and tried the hazard. Success. Then I turned the key to run and everything acted normal. Love you, Hapy. Root cause: current owner error not tightening the positive battery cable on the battery post after changing the wiring. Sigh, sometimes are better than some times.

I pulled the positive cable off the battery and re-assembled the dash. While I was there, I cleaned all of the fuses and their connections with rubbing alcohol, and then zip-tied the fuse box up out of the way (it has never been screwed to the bus since I bought it). With the front-end cleaned up, I put the positive cable back on the battery (still sitting on the bumper) and checked again that things were normal. With the key turned to run, I checked the voltages on the flat-connector, and now the pins aligned with the table above.

Test Fire

battery on "bumper"

Feeling confident, I turned off the key, plugged in the new accelerator pedal and test fired the bus. Engine started, sat at idle, threw no codes... and working the pedal with my hands revved the engine. Hazah! To complete the loop, I removed the battery cables from the battery, and put the battery back in the bus. While I was there, I resolved some wire routing, and implemented a battery strap-down with the webbing I used to hold the speaker box in the MGB trunk (See Speaker Box Install Finish). This also is holding the battery-top fuse-box on top of the battery. I returned the battery cables to the battery posts (this time tightening them down) and did another test fire. Start, run and rev. With all the wiring and cables now sorted, I was able to re-install the original engine hatch prop, which means no more holding it open with either my head or a stick (like in the picture on the right, here, you can see a stick all the way to the left). More winning. And, of course, I bolted the pedal to the support post and tested the foot feel before heading inside for a celebratory smoothie.

The next day, I set out re-test the old pedal to see if that small resistance difference between pins 2 and 4 was meaningful. It isn't. The old pedal works correctly now, just like the new one: no codes, engine rev's. Since the new pedal is bolted in, I decided to leave it, and put the old pedal into my parts bin. In the end, the sporadic P0121 error that Hapy and I have suffered for the last few years was ultimately caused by something in the wiring that I replaced with the front-to-back cable at the start of the Chasing Electrical Gremlins saga (See part 1). Still, I will be putting the old pedal in a large Ziplock baggie under the rock-n-roll bed in case this new pedal fails on the road. So, this completes my efforts with the P0121. I hope the resistance and voltage (courtesy of TDIClub) information above is helpful to others as you diagnose your own P0121 error. 

Thanks, as always, for following along-

P0121 - the 1200 rpm limp mode - Part 1

Today, I will start to go through my efforts to identify the cause for my P0121 - Intermittent Signal from TPS issue. Yes, I know! Another multi-part series?!? Well, that's how it goes when we need to wait for shippers. Anyway, the process I followed is similar to what I did for the other wiring issues I just resolved in that there is a logical approach, but otherwise, this is about solving a 6-wire circuit and really shouldn't be a big deal. But it was and here we are.

Drive-by-Wire

drive-by-wire pedal

For those who haven't suffered from this code before, or may not even know this is the code you are getting, I'll start with a quick summary of what this is about. In modern drive-by-wire cars, your throttle pedal may not actually control the speed of your engine or vehicle directly. If you have watched some of the car shows on MotorTrend, when an older car (pre-fuel injection) gets a modern engine (with fuel-injection), they need to add a throttle position sensor (TPS) to tell the computer how far open or shut the throttle is. In these conversions, the TPS is usually connected to the throttle cable in the engine bay. This converted the pull/push of the cable (which reflects the push / let-up of your foot) into a signal the computer understands so it can figure out how much fuel to throw in, or how to adjust the timing of the spark. Cool, eh?

 

New cars, whether they are burning volts, waste cooking oil or dead dinosaurs, do not have a go pedal hooked up to a cable any more. They skip the middle man and have a TPS wired up to the pedal, so your pedal works like a big fader (light dimmer) or rheostat. The TPS converts your foot push / let-up into different voltage that gets sent to the computer where it does all the things I mentioned above.

P0121 - What Is It

All this is great. I mean, having something that precisely collecting your speed wishes and implementing them without a mechanical component seems pretty fantastic. And, it is, until that day when you are driving along and suddenly the pedal no longer seems to translate into speed. You notice that no matter how you position your foot, the engine speed doesn't vary. In fact, you note that the engine's speed has become static. I can't speak for other makes and model years, but if you are in a VW TDI circa 1998-2004 the engine will be pinned at 1200 rpm. Adding color to the scene will be the illumination of the check engine light. Your first impulse may be "oh snap, the engine is broken". Not so fast. In this case, you are probably getting code P0121: Intermittent Signal Inconsistency from the Throttle Position Sensor.

That sounds awfully scary, but in cars that were not hacked up like Hapy, this is probably caused by your TPS failing. It happens. In VW's, this is one of those rare parts that do not fail super-often, but when they do they are actually kind of easy to replace. You remove the panel under the dash, unplug the flat-connector, remove 4 bolts and it's out. Replacing the one in Hapy is just as easy, but determining that the TPS is the root cause is not. In Hapy, we have 6 circuits running through 7 meters of wire and multiple connectors. In your car, the 6 circuits probably run for less than a foot and run from that flat-connector to a T10 or something similar. No extra connectors, no super-long wires.

Hapy Diagnosing Plan

Before I pulled out my multi-meter, I gave myself a few minutes to think about the situation. I had intermittent P0121 codes getting thrown since I before swapped out the original 1998 NewBeetle one-year-only TPS for the more general-use one for model years up through 2004. The original TPS had the 6-wire bundle pressed against the underside of the bus, and eventually the plastic wire casings wore through. The wires grounded against the body, causing the original P0121 errors. The general-use pedal threw codes intermittently and was one of the drivers for the replacement of those wires with the front-to-back cable. That cable runs from just after the flat-connector all the way to the blue T10 (through another T12 connector). So, either some part of the wiring was done wrong or it was never the wiring all along, and it had always been the TPS or the flat-connector or both.

 

A side note about the wire sizes. The wires coming out of the VW 6-pin flat-connector vary in thickness from 22 or 24 up to maybe 18 (probably more like 20). Since the resistance of the wire is inversely related to it's thickness (thinner = more resistant), by replacing the old thin single wires with a thicker well-jacketed cable, I effectively reduced the resistance of the front-to-back run. According to this calculator, the wires in the new cable should be around 0.03 ohms. The old wires, being 22AWT gauge were around 0.3 ohms. Noting the decimal point, the old wires were 10x more resistant to current. So, we can exclude any concerns about the new cable wire size being a cause; quite the contrary, it should be delivering electronic messages better.

A failing TPS or a bad flat-connector sound like great theories. Let's prove it. I chose to start at the flat-connector and work back to the ECU. I have a second flat-connector in the heap of spare or removed TDI stuff in my garage that is also 6-pin, so I can swap-out the in-Hapy one if necessary. This also provided me the resistance values for a 6-pin flat-connector that is otherwise "normal". With the multi-meter at its most sensitive setting, I tested the resistance of each pin -to- end-of-wire. After the plug was warm in my hand, the resistance value was "3". Prior to that, when it was cold from the garage, the resistance was closer to "8". Since they were all within the same order of magnitude, I wasn't too concerned. That's our baseline: less than 10 on the most sensitive setting. With that, we bundle up and head back out to the bus.

Hapy Wiring at TPS

6-pin to
front-to-back cable

First, I unplugged the flat-connector, peeled back the plastic wire protector to where the wire splices were and then, with a razorblade, cut a small slit in each cable wire just past heat-shrink so I could touch metal with a probe. You can see the repairs to the wires in the picture on the right. The blue wire is probably the best visual example. Then, from 1 to 6, I checked the resistance to make sure they were all less than 10 on the most sensitive setting. To keep variables down, I held the flat-connector in my hands for about a minute first. It is still cold (4*C) here, even if I'm not complaining about it in every post. Apparently, its not a cold winter, I'm just a sissy working outside in it. So be it. Anyway, they were all very low, like at or below a "2" on the most sensitive setting. This told me that the flat-connector was good and the wire connections between the flat-connector and the cable were good. Very good, actually.

 

While the 6-pin flat-connector was out, I addressed the TPS plug socket with DeoxIt D5 according to the instructions on the can. I figured that if our problem was a simple case of the contacts getting worse over time, we would see a some improvement from this. I covered the little slits with electrical tape, and took a picture so I could reference the color-to-color later. I re-wrapped the wires in the plastic covering and moved to the back of the bus. I left the 6-pin flat-connector disconnected so the contacts could air dry.

Hapy Wiring at Engine Bay

T12-to-donor (T10 blue)

In the engine bay, I confirmed that the blue T10 and grey T12 plugs were snug. I would have had other issues if they had not been, but diligence wins electrical issues. Then, I pulled back the plastic cable wraps and took a picture of the T12 wires from pins 1-6 and then a picture of the color-to-color connections from the T12 to the wires which run to the blue T10. I compared these pictures with the wiring diagram I had constructed and believed all of the wires were routing to the correct partners. So far, so good. The next test was to confirm continuity between the blue T10 pin and the originating pin on the 6-pin flat-connector. This would demonstrate that the wiring from end to end is clean.

 

I was not really sure what to expect, resistance-wise. Before I could do anything, I needed to close the circuit, so I grabbed a long solid-core wire I have used to test with in the past. My testing process: I would gently insert a bare wire into the pin-hole in the flat-connector, and run the rest of the wire spool back to the engine bay. There, I measured the resistance between that wire end and a pin in the blue T10. I had difficulty figuring out which pin was "1" versus "4" in the blue T10 and the pattern from wire to pin seemed illogical. Unfortunately, had I really internalized that, I would have potentially found the root issue. When I found a connection, the resistance was down in the single digits in all cases. So, we can rule out the new wiring... ish: I discovered later that when I wired up the blue T10, I crossed up 3 of the wires. I didn't realize this until later (hence the 2-part post as I lost a bunch of time going down a wrong road). So, I continued forward believing that the wiring was right. Since I learned a bunch about the pedal along the way, I felt it was worth retaining all of this content.

 

Hapy TPS

Since I thought there were no wiring issues, I figured that the TPS went bad. I first thought that maybe I broke it by stepping on it all the way to max, and it needs a movement stopper or something. I looked at the way I installed it; the floor and the carpet would have acted like a prevent against over-pressing the pedal. After doing some research, it seems like these pedals are prone to failure if they get wet. Since Hapy is parked outside, and last year his fancy BusDepot cover effectively held water in rather than out, if the pedal had been steadily degrading because of the damp conditions over the winter (and sometimes in the Summer around here), then this seems a fairly reasonable explanation for the persistent, recurring P0121 code. I figured that last winter's super-damp caused the pedal to finally fail so I ordered a replacement.

 

That's it for today while we wait for the replacement pedal to arrive. More next time about resistances, voltages, etc as I examine the pedal and the pedal wiring and, ultimately, fix the P0121 error.

Chasing the Hapy Electrical Gremlins (part 4)

Before I begin, I hope we all have a 2021 that allows us to all forget just how bad 2020 was. That really capped off quite a decade. Anyway, with the new decade now in front of us, let's all work together on making our little worlds more friendly, livable and Hapy. On that, I spent way more hours than I could count over the last few weeks clowning on this wiring. I work slowly, so even when I have a huge block of time, meticulous work takes nearly forever. I got so carried away in fact, I missed my usual posting day this week, so this one is a little late. HNY!

 

Wiring Diagram

I have completed the wiring diagram. I mentioned in a comment on that last post that I had to start over because of differences between the Jetta and New Beetle of the same year. So goes. I now have a 12-page custom wiring diagram for this build. It includes things that I have not yet completed nor posted about (like a glow-plug light), but it does NOT include anything about the original bus. So, when working on something related to the TDI, we use this new one. When addressing something in the 50-year old transporter, we reference the Bentley. I expect that I will be making small modifications to the diagram based on what happens during the harness surgery. I figure that if the diagram isn't accurate, it really isn't very valuable.

 

Complete the Cut-Apart
When I last posted, I was in the process of cutting down the part of the wiring harness that ties into the fuse box and relays. I have worked on this area before. In retrospect, I maintain that leaving the engine harnesses that go to the ECU untouched is the right answer. I had looked at cutting them down too, and concluded that is playing with fire. Besides, just this one harness was quite a time consumer. This harness has the T10 plugs (white, black, orange, blue) and a T6 that in the NewBeetle's case is red, but on other cars it is brown. As I mentioned, this also has the fuse box, and relays. It also includes the dashpod, an OBD-II plug, an oval "T10" that is also black that lives in the engine compartment and there are a handful of little 2 or 3 pin plugs for the alternator, air conditioning and coolant level. It's really a random collection of things; making a decent custom harness from it is not all that easy. Anyway, my goal was to label-label-cut enough so I could remove the harness and thin it out. After the over-zealous cutting I mentioned in my last post, this was going to get much bigger. I got the last few of that "handful of little things" label-label-cut so I could bring the whole thing onto my kitchen table. I will get into the thinning in a future post (probably my next one).

Install Plan

Few things that go well happen purely accidentally. You have to make a plan. With the fuse box, relays and dashpod out of the way, I could re-assess the spare tire well which I'm now calling the "wiring compartment". I need to keep the dashpod wired-in for the engine to run correctly. Since it is rather small, I planned for it to go into the far end of the compartment, with the rounded top slightly pitched so I can see it when I'm tinkering with the compartment exposed. On the other end, nearest the rear hatch, I planned to put the ECU, with the new fuse/relay box in between. For this to work, I'll need to shorten many wires in the harness I just removed, but the result will be a wiring compartment with a few cables, but no spaghetti. The T10's will plug into the thicker ECU harness below deck, so there will be some cleaning, arranging or obfuscating I'll need to do there.

Dashpod Mount

The donor pieces I received included the plastic surround for the New Beetle dash. The front/top cover snaps in place, hiding the screws that hold the dashpod to the plastic mount. This cover, however, makes the dashpod too wide to fit in the spare tire well, so I tossed it. I also had to cut down the plastic mount so it would fit, leaving the front-most flat section and the lower plastic bits that support the screw-holes for the dashpod. The second picture from the top shows the dashpod in 2 pieces. The upper 2 pieces were cut apart. I set and reset, fiddled with and eventually arrived at a spot for the dashpod. I marked holes, drilled them out and sent long screws thru the dashpod mount into the front curved side of the tire well. The dash pod clicked into place, and was quickly screwed into place. I checked clearance for the 2 cables that click into the dash pod, and there were no issues.

ECU (computer) Mount

Mounting the computer was not as simple. I received what looked like the plastic ECU holder back when I first got the New Beetle TDI, but I could not figure out how to orient the ECU so it would fit between the base and the protective flap door thing. So, I tossed the base, and screwed the flap door into the spare tire well instead. The ECU sits quite nicely on there and the cables are unimpeded. I will need to either Velcro the ECU to the mount or use something else. I will use short hook-end straps (like these) for now, since I have a few of them, so they are free. I intend to treat myself (and Hapy) to a Malone tune, eventually. I'll go Velcro after that, since I don't know how the Malone tune thing works with sending a computer in or if you get a flash download or what. Something to learn, and post about later, I guess.

Fuse / Relay Box Mount

final-ish look

With the ECU and dashpod located, there was really only just enough room for that fuse/relay box to fit between them as you can see from the picture on the side here. I chose to locate it on the inside of the wheel well, but it could just as easily gone on the other side. This way, the fuses are furthest from the rear hatch, but the orientation is consistent with my drawings (where I have the fuses at the top). This was a relatively simple matter of aligning the top of the closed fuse box with the top of the rear deck, marking the spots and boring them out. A standard hand drill doesn't fit there, so I put the drill bit in my Dremel. That is probably not the best solution, so I don't recommend it, but without one of those fancy 90* air-powered drill things, we make do with what we have.

 

That's it for today. Next time, I intend to get into the harness surgery. Thanks for following along and Hapy New Year-

TDI install retrospective: ECU, dashpod and Sensors

Continuing, or should I say completing, the process of back-documenting what I did to put a TDI engine into an old (1972) air-cooled VW bus. Today I cover whatever is left of the install that I didn't already cover. I had intended to focus this post on the ECU, dashpod and sensors, but most of that stuff was covered the last time.

ECU

ECU image nicked from eBay

Like any modern car, the ECU is the brain of the outfit. It's rather small, for what it does, measuring around an inch thick and around 4 x 6 inches rectangular. There are 2 large rectangular plugs that slide and then lock in. One of them is for the harness that goes to the engine. The other does everything else. The engine harness is the more important of the two, but only just barely. I was able to leave that harness almost completely untouched. I just unwound some tape here and there, but otherwise, it routed like the stock TDI implementation. I left the AC compressor plug dangling where the AC compressor would go, but everything else plugs in. Because of the ECU location in the spare tire well, the harness did not need to get extended at all.

The other (non-engine) harness gets interesting. This is where the majority of your sleuthing will take place. Many of the wires go to the fuse box, and many of those fuses are not needed for our implementation. I chose to leave the wires from the ECU to fusebox alone. Instead, I pulled the fuses for the unused circuits and then removed the wire from the other side. This left less of a mess than had I left everything there, but also reduced the risk of removing something I had to put back... Which happened. Other wires go to the dashpod or the relay blocks. I can't really advise much more on this other than to take care as you decide whether a circuit is needed for your implementation or not before you cut it out. Kind of like that "measure twice, cut once" axiom.

Dashpod

TDI Beetle dashpod

I took measurements, and early-on thought about how I could retrofit a TDI dashpod into the bus dashboard. The VW Beetle dashpod is a single mostly-circular (shy of 270* of a 360* circle) face with a thick surround. It could not fit without some modifications to either the dashpod or the bus dashboard or both. I also own a Jetta of the same vintage and took measurements of that dashpod. I probably could have fit that, but then I would have had to re-think a few things, starting with the speed sensor. More importantly, the ECU and TDI fusebox were in the spare tire well 10 feet or more behind the driver seat. In order to get all of the signals to the dashpod, I would need to extend 30+ tiny wires and hope for no signal loss. Instead, I left the wires alone and buried the dashpod in the spare tire well. The engine will not operate without the dashpod wired in, by the way.

FuseBox and Relays

fuse box image nicked from "PopScreen"

As you work your way through the circuits you don't need, eventually you will work your way to the relays. You don't need many of them. Of course, you need the 109 power relay and the glow-plug relay, but as you remove the things you don't need (cooling system pre-warming glow plug circuit, for example), the support stuff falls off along the way. I have both the fusebox and the remaining relays, still in their respective relay holders, living in the spare tire well.

As I mentioned in the secondary electrical post, I will be re-visiting the wiring in the spare tire well as part of my seasonal readiness this Spring. I would like to re-run the wires from the front-to-back using a single cable as well, making the wiring seem more purposeful.

Idiot Lights
I mentioned that the original bus has 2 warning lights (well, 3 if you include the brake warning light). One says your engine is toast and the other says your electrical is fried. Not very useful, but they're better than nothing. The TDI has a few things worth warning you about too. First is a Check Engine Light (CEL), sourced from pin 24, it gets voltage when a code is thrown. Second is the glow-plug light. This will tell you when the engine is ready to start when it's cold. It will also flash at you when certain error conditions occur. This second reason makes the case to have something. Next is the coolant light. This lets you know when you're low on coolant and on the TDI cluster it flashes for some error conditions. Again, good to have. Last of interest are your charging system and oil pressure, just like the old bus had.

If you look back through the blog, you will not find any posts about this. Why? Well.. truth be told, I didn't do any of these. I run the UltraGauge and that alerts me of any code being thrown, so I don't need a CEL independently. I don't run the bus when it is cold, yet, so I don't need a glow plug light yet. When I do, I will tie into the glowplug circuit to light when it is energized. That's a cheap way of getting there. Others have tied into pin 40. For the coolant level warning, I will tie directly into the 2-prong sensor in the coolant bottle. Frankly, I probably should have done that a long time ago. The charging system could be a simple relay that sends a signal when the difference between the battery posts is below 12V. Alternatively, you can create a "real" alternator light by sending switched 12V to one side of a 12V bulb and the other side to the "exciter" terminal on the alternator (labelled D+ or L). The oil pressure is actually complicated because the TDI cluster determines whether the oil pressure is low for the engine speed. If you really want an independent oil pressure message, it might be worth getting an after market gauge. I haven't decided whether I want that or not. I like the simple dash I have now, though the UltraGause does not include oil pressure. So, this is a continuing risk, for now.

I hope these retrospectives were useful. I realize I neglected to re-iterate the deep details that appeared in the original posts. That seemed excessive. Instead, I focused on the big-picture things that worked, expecting interested readers to leverage the search function in the blog or to follow the links when I did it for you.

Prior related posts:
Preparation
Fuel System
Physical Mounting
Vacuum System
Air, Intercooler and Exhaust
Primary Electrical
Cooling
Secondary Electrical

Now that these retrospectives have been completed, I expect my postings to drop off for a while. I have a number of projects all starting up at once, so while I will be generating content, it will be a while before any of them reach a point of post-worthiness, much less align on the weekly cadence I've been on for the last 2 years.

As always, thanks for following along, and I'll get back to posting when there's something complete enough to write about. Peace, Love and Smiles-