Returning to Oliver

The last week or so has been busy with lots of not-car stuff. We have had our young niece over a bunch while her mom had surgery on her wrist, and a bunch of social events. Of course, with the return of spring comes the return of recurring yardwork as well. So, I have not had the dedicated time for wrenching that I always seem to think will be available. I was able to get out to the shop for a few hours on Sunday, though. I focused on Oliver, the 1978 MGB, letting Hapy ('72 VW microbus) sit until Justin has his time with the injection pump in April. The rate at which the price of diesel fuel is climbing (passed $6US/gal around the corner), I may find that it costs more to fill his tank than to pay Justin for his time. That's totally upside-down. Anyway, back to wrenchin.

 

Voltage Gauge

remember Oliver?

I installed a Smith voltage gauge into Oliver where the original analog clock used to sit. The clock didn't really work very well, and it ate voltage from the battery when I let him sit for too long. This made the clock less accurate, leading me to pull the positive cable off the battery while not in use. This led to the clock being completely worthless. So, I pulled it out and swapped in the voltage gauge. It seemed like a valuable bit of info to have, but I had wired it into the "purple" or always-hot circuit. Like the clock, the voltage gauge slowly drained the battery down, albeit not as quickly. So, again, I pulled the positive cable while not driving. I changed that on Sunday.

 

Bearing in mind that any entry back into working on cars may not seem like a big deal to regular wrenchers, but I have really not done much car stuff in over a year. So, any steps taken are a big deal. Removing the gauge was simply unwinding the knurled nut holding the rear support and the gauge flopped forward out of the dash. I removed and taped-off the "purple" wire and started seeking a viable switched "green"source to tap into. Switched is available at a few spots, but I decided to run a dedicated line from the fuse box instead. I could say I did that to remove variables or variability in the voltage signal. The truth is that Oliver is parked so close to the side wall of the shop that getting in and under the dash was virtually impossible. I was not going to just start grabbing an unplugging things.

 

Smith voltage gauge

Running another wire is simple enough. I started at the gauge and worked my way behind the dash, center console, and glove box to the firewall pass-thru. From the pass through within the engine compartment, the bundle of wires run along the left fender to the fuse box. I tied the new wire into the existing green bundle and tested continuity with the multi-meter. Success! I installed the gauge, hooked up the battery and tested by turning the ignition to "run". The voltmeter slowly crept up and I could hear the fuel pump banging away. I recall that it used to get quieter with fuel in the pump. Satisfied, I turned off the key and looked for any other parasitic drain on the battery. The wires in the engine compartment need some containment. I am not liking the scattered multi-colored angel-hair look in the picture below right.

 

Battery Drain?

technicolor angel hair pasta wiring

Testing for a parasitic drain on your battery ought to be relatively straight-forward. Disconnect one cable. Set your multi-meter to test for Amps and then place one probe on the battery post and the other on the cable end. All 0's? Switch to milli-amps and try again. According to the internets, if the drain is less than 50mA, it is not enough to drain your battery. I got 0mA, which, honestly, I do not believe. I tested it multiple times, and even after cleaning the cable and the battery post, I still got 0mA. So, I checked voltage across the 2 posts (12.08V) and left the cables attached. I figured if the voltage drops overnight then my battery-drain test will be proven faulty. I have since tested the voltage the last 2 days. The battery loses 0.02V overnight, which I think I can attribute to the stereo. Regardless, I will need to add a float charger.

 

Red Rollie

new lock, locked

I have this old red Kennedy tool cabinet we call "Red Rollie". It houses a bunch of tools, and for most the nearly 20 years that I've owned it, the lock didn't work. Well, I didn't have a key for it. We got the cabinet at an estate sale without the key. Anyway, some tools were stolen from my next door neighbor's yard a few months ago, so that changed our vector regarding the shop. We were perfectly fine using it without doors, but I can't leave entire tool cabinets unlocked if thieves have found our quiet little neighborhood. While I think the theft next door was an inside job (they run a construction business out of their home), one can never be too sure. So, I found a lock that fits this old Kennedy cabinet (Kennedy 80403 High Security Tubular Lock), and replaced it.

 

Replacing one of these locks is actually easier than on newer cabinets. The lock is held on with a U-shaped tang that slides off to the side. The hard part is you can't see anything. With my fingers I was able to determine which direction the tang needed to slide to be removed (facing the cabinet, slide right), and then set a stubby slotted screw-driver against the lip of the tang. It only took one well-leveraged push to get the tang removed and the lock to pop out. To install, orient the lock so the little inner divot on the outside facing part of the lock where the key goes in is facing down (unlocked). Set the lock into the hole with one hand while guiding the locking rod into the rectangular hole on the back of the lock. Then, push the U-shaped tang in place to hold it.

 

Red Rollie

This worked great, and effectively locked the top 2 drawers. The 3rd drawer down, however, had been bent where the little hook pokes out the back. To remedy, I got a framing hammer and a 1/2" ratchet extension and beat on it until it was more-or-less flush with the rest of the rear of the drawer. For years I wondered why that drawer always set deeper into the cabinet than the others. Now I knew. Once the drawer had been persuaded, the drawer fronts lined up and that 3rd drawer locked as well.

 

Wrap

That's how I spent my Sunday afternoon. The shop still needs the 2 largest doors, but my tools are secure, and I am really starting to get comfortable in there. For example, there was a period of time while working on Oliver that the skies opened up and it started pouring rain. I never felt it. In fact, I could only hear it hitting the trees. The insulation on this shop stops the sound of rain on the steel roof. I absolutely did not expect that.

 

That's it for today. Next week is Easter, so I may not get out to the shop for much. I hope to put a little gas into Oliver and at least back him out to where I can give him a deep cleaning. 

The Ghost of GoRo

I have been coming off of an illness, having been sick for almost a month. Yeah, whatever that thing is going around got me good. In the meantime, we have gotten some headway on the shop doors and I got to start thinking about what's next on Oliver to get him on the road for the Summer. Today, though, is a cautionary tale about selling a car, no matter who you sell it to.

 

What's GoRo

GoRo

I'll back up a little bit first. Back in June of 2023, in my "Small Fence, Big Difference" post (link here) I mentioned in passing that we had sold GoRo, our 2009 Audi A4 to a guy down the street. We told him multiple times prior to closing the sale that he really did not want the car, that there were weird issues with the transmission, interior plastic bits were breaking off and that it was a generally crappy car. He would not heed our concerns, saying it was for his daughter, he could get the mechanicals fixed up fine, etc. There was still a couple of months left on the existing registration, and he was going to have to drive it to his mechanic, and then over to Department of Environmental Quality (DEQ) to get registered. So, Boo with her ever generous heart, let him take the car with the tags on it. We went inside and recorded the sale with the state of Oregon immediately.

 

Sales Daisy Chain

Of course, we were right. He took the car and within a couple of weeks he had sold it. But, he didn't tell us, nor did he remove the tags that we had left on there for him. In Oregon, you have a month after buying a car to change the registration. Since he hadn't had the car for a full month, he was officially in the clear, but whoever he sold it to also sold it within a few days, and we lost the handle on the ownership after that. 

 

Ticket Parade 

Why is all of this important? Within a few days after our

barn door

neighbor sold the car, we got our first of many speeding or other moving violation caught-on-camera ticket, followed by parking tickets and toll-lane charges. We got tickets from Montana, Texas, California and Colorado. In each case, we sent copies of proof that we no longer owned the car. For the tickets which came from legitimate state, county or city governments, the tickets were waived. In the case where the ticket was for not paying a toll on a "private road", the charging entity did not care that were were not the owners and could prove that we were not even in the state at the time of the violation. Instead, they sent the ticket to collections, dinging our credit. To prevent further damage to our credit, we paid that one. Most of these tickets arrived within the first 6 months after the car was sold.

 

Final Straw

This week, we got what we believe to be the final ticket. GoRo had been impounded in the City of Merced and would remain in their custody until we came down to their office and paid the bail on parking tickets. We don't care and after a while they will put the car up for auction, and it will be someone else's problem. I just hope the auction house or the City of Merced removes the license plates before handing it off to another sucker.

 

Buh Bye GoRo

barn door, inside

By the time we sold off GoRo, Boo and I pretty much hated the car. The seats were stiff like bleachers, increasing internal switches were failing, plastic bits were falling off, the transmission shifted funny, etc. It outside looked great, but wow, what a lemon of a car. The lesson here for us and for you: even if you're selling the car to your friend, remove the tags. If you are all down for the sale and want to be generous, drive over to DMV and remove the tags while your friend is getting temporary plates. Once that car leaves your possession, there is no telling what will happen to that car. You could find yourself with a big pile of tickets from uninterested parties who only want money, and are willing to hammer your credit to get it.

 

Car and Shop Stuff

I mentioned at the top that we have made headway on the doors on the shop. Recall, I have 4 openings which need closings. Over the past month, our friend Ray has built barn doors for the large opening facing west using extra siding I had added to the order for the shop so those doors could get made. It is a 10 foot wide opening, so the doors are each just over 5 feet wide. They totally look the part and glide open/shut easily. We also installed a "people door" on the north elevation or facing the farm house. This leaves a 8 foot wide doorway on the backside and the main large garage door next to the people door. I have been saving for the big door. While that doorway is a standard 16' wide, it is 10' high (just in case someone comes along with something really big, I guess). So, it is a semi-standard door.

 

On cars, I have Hapy about as ready to visit Justin as I can make him. Since he hasn't really driven since I put him back together, I really would have liked to have driven him a little more. With Diesel hitting $6/gallon around here, I all the more do not want to be driving with a fuel leak. So, his next drive will be to Justin's place.

 

voltage gauge upper right

To keep my hands busy, I have been looking at Oliver, the 1978 MGB. I couldn't get him to start when I went to move him into the shop and I didn't really look into why at the time, I just hauled him. I slid under the rear end and discovered why: I had drained all of his fuel out the last time I parked him. If I remember right, I put that fuel into the lawn tractor and the rest into Astra. Antyway, I test-fired the fuel pump with 12V directly from the battery and the fuel pump works. So, if it does not come on with the ignition key-turn, it's a wiring issue. After messing with that, I removed the voltage gauge from the dash and will be sourcing switched power for that. I had simply used the always-hot 12V for the clock I had replaced, but that runs the battery down eventually. I hope to have some time this weekend to finish the voltage gauge, put some gas in and see if I can get him to run, and idle. Then maybe I'll back him out and give him a long overdue bath and a drive-around.

 

Well, that's it for today. Keep your license plates when you sell your cars, and thanks, as always, for following along- 

MGB Battery Monitoring

Sometimes, when you're working on one thing, it is a really good idea to take your mind off of it by working a little bit on something else. Today's post covers my distraction from Hapy's electrical issues.... with the battery issues on Oliver (the 1978 MGB). LOL. For my local-to-the-Pacific-Northwest friends, I hope you have heat and power. I know some friends have been without both since Friday. Grateful we are finally above freezing.

Flat Battery

Our saga begins with Oliver's battery going flat from being parked for a few weeks. I first noticed it in early fall after parking him in the garage for the winter and forgot to hook up the float charger. When discovered, I put the battery on the float charger like when it was parked outside, but wanted to know the root cause. I started with swapping out the battery for the battery we had pulled from donor Zed. That was a good battery that still held 12.5V almost a year after pulling it out of the donor. It barely fits in the battery box, but it would run flat if left off the float charger when hooked up to Oliver's battery cables. I decided there was something pulling vampire amps off the battery.

Clock

original oil temp
and clock look

I am sure there are faster, more scientific ways to figure this out, but this is what I did: I pulled all the fuses, and put the battery cables back on the battery. I left it like that for a week and found that the battery did not run flat. This told me that the drain wasn't from some ShadeTree wiring that did not run through the fuse-box. Then, I checked the amp draw across the fuse pins, and found that the draw from the bottom-most fuse registered on the meter. That fuse provides power to the interior lights, the trunk light and the clock. These old analog clocks consume much more power than their digital counterparts, because they need to run little motors that turn gears rather than a tiny computer to keep the time. I decided I would pull the clock and put in a gauge that might be more useful: a volt-meter.

 

This removal is interesting. The VDO gauges with which I am most familiar have a threaded collar that goes all the way around the base of the gauge. You push the gauge through the hole in your dash and then thread on the collar from behind. These original MGB gauges are not like that. Instead, there is a cross bar that is shaped like a "U" with a hole through the very center of it. That hole aligns with a threaded stud exiting the center front (again, front is front) of the gauge. Once the stud passes through the hole, the ends of the "U" press against the dash, and a nut is threaded on to hold it in place. While more elegant, it is actually harder to manage with 2 hands. Otherwise, I think it is the better mount because you can wire your gauge while it is dangling through the hole in your dash, test it and then mount it without disturbing the wiring. With the VDO mount style, you need to either be optimistic and run the wires through the collar suspended behind the dash -OR- do that after you have tested.

Volt Meter

volt-meter installed

The gauges in the old MGB were made by a company called "Smith". So, if you want your gauges to look authentic, it is best to buy Smith gauges. Here in the US, that is quite difficult to do in-person or at least within the borders. Enter eBayUK. I found someone selling off a perfectly good voltmeter that was era-correct from a different British car. It cost about $100US delivered, and it arrived faster than some other things I have gotten from the east coast. The wiring is quite simple. there is a ground protruding from the front (front-is-front) corresponding to the far bottom end of the voltage scale. On the other side, opposite the top-end of the voltage scale is the signal input. In-between is a tube into which a bulb is set. This requires the bayonette-style bulb similar to the clock, and the other gauges in the MGB. I just reused the one from the clock.

Testing

Of course, I could not just pull the clock and slap the voltmeter in without some tests. First, I wanted to see how/if it worked. So, I ran a wire from the negative post on the old MGB battery (sitting on the garage floor on a float charger). To the positive post, I ran a fused wire (wire to a fuse to another wire) to the supply-side of the voltmeter. The needle slowly moved up and settled just below 13V. Perfect.

 

Next, I grabbed the clock I had removed. I confirmed that the clock would run using the same test wiring set up first. Then, between the fused wire and the supply side of the clock, I ran my meter to see what the amp draw is. On the second to most sensitive setting... or is it least sensitive.. setting, I got an amp draw: 30. Interesting. I did the same thing on the voltmeter and got 3. So, the clock draws 10x as much juice from the battery as the voltmeter does. I figured that the voltmeter, even if it was on all the time, would allow the battery to hold a start-able charge 10 times longer. So, I decided that running the voltmeter to a switched source was not necessary. I may revisit that one day, but for now, I figure that I can look into the window of the car and see if we can go for a drive. More importantly, I could simply re-use the wires that I had just removed from the clock.

Install

volt-meter test with 
running lights on

Installing the voltmeter was quite easy. I plugged the red/white wire into the light bulb I scavenged from the clock. I plugged the black ground wire into the ground and the purple wire that used to run the clock into the voltmeter sensor plug. I confirmed the wiring by putting the battery cable back on. Yes, I could have done something with less potential for failure, but I would have had to do something like this eventually, and it was only 3 wires. I wrapped the end of the purple wire with electrical tape so I didn't accidentally short the circuit (and pop that fuse). Then, I set the gauge into the hole, put on the "U" with the arms touching the dash such that they were not anywhere near the supply side (running approximately from 1:30 to 7:30 on a clock-face). A quick thread-on of the retaining nut and it's in.

Between the weather and the pile of non-operational cars in the driveway, I cannot take Oliver out to test the gauge. But, since I hooked it into the always-hot circuit for the interior lights, I can verify that it works simply by looking at it. It currently reads just under 13V. So, we're good. I intend to leave the battery hooked up without a float charger and I will be checking the battery condition every couple of days. If the voltage drops enough for me to notice (or below 12V), I will put the float charger back on. at that point, I may search additional vampires. At this point, I think I slayed the one that was draining the battery.

That's it for today. 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-