Tuesday, December 19, 2017

Dashing Thoughts

Today's post is just musings about how to improve my visibility into the health / well being of the diesel engine pushing the VW bus without retrofitting a NewBeetle or MK-IV Jetta instrument panel into the spot where the current original dash lives. This is actually all related, though it may seem a little scattered. I blame the holiday season.

With a planned change in tire size, the speedometer will no longer be accurate. It's really more of a guide as it is. I know there are converter bits that can be attached to the cable to gear up and down, but I'm not really sure how well those work. There's the option of doing surgery on the speedo, like this page here suggests, but that's a little scary. Still, if I want the original speedo to show the right speed after putting larger tires on, is does read like a viable alternative.

I could figure out a means of getting the speed from a Hall-effect sender. These are basically a magnet on the rotating wheel and a magnet sensor picking up the magnetic field as it passes. This signal is effectively a square wave that an electronic speedo can interpret. OR, the computer could know how fast I'm going, if I route the signal to the ECU. But, I'd still see the old needle on the original dash, showing the wrong speed. I like the idea of being able to keep the original dash operational so I may need to do something to the original speedo no matter what I do about the ECU.

I am currently unable to determine how much fuel is in the tank. I tried swapping out the fuel gauge when I thought I had confirmed the sender was good, but that didn't work. So, I have to consider that the fuel sender has failed. If replaced with a ALH-ranging sender, the computer would know the fuel level. But, that would also mean that the fuel gauge on the original instrument panel wouldn't work. So, maybe I could figure out a way of installing an original sensor in the tank and then splicing a second signal from that, but shift the signal in the second signal to match the modern sensor.
Original VW Bus sensor       TDI
10ohms (full)                          35ohms
75ohms (empty)                    285ohms

If the bus range is 65ohms and the TDI computer expects a 250ohm range. For each ohm change in the sender, I'd need .26 ohms of change. Plus, the floor resistance would need to be increased by 25ohms. I haven't done electrical work like this since high school, but I'm not sure how this would work. In the table below, I've split the target ohm values into 13 5ohm increments from the original bus side. The diff column represents the difference between what the sender would provide and what the TDI gauge would expect. The step increase is the additional amount of resistance needed from the more-full to less-full increment. Nothing is simple.
Bus diff step increase TDI
full 10 25 25 35
15 39.23077 14.23077 54.23077
20 53.46154 39.23077 73.46154
25 67.69231 28.46154 92.69231
30 81.92308 53.46154 111.9231
35 96.15385 42.69231 131.1538
40 110.3846 67.69231 150.3846
45 124.6154 56.92308 169.6154
50 138.8462 81.92308 188.8462
55 153.0769 71.15385 208.0769
60 167.3077 96.15385 227.3077
65 181.5385 85.38462 246.5385
70 195.7692 110.3846 265.7692
empty 75 210 285

Maybe, I could get a converter like the Fuel Gauge Wizard. These are designed to meet this problem for any gauge/sender pair which provides less resistance the fuller the tank and is empty at 500ohms or less. I could splice it in to the original wires so the stock signal is untouched while the new signal goes to the ECU.... hmm... Then, the stock gauge could still read while also informing the ECU to support the digital gauge.

Back to Dashing

If I had solved the fuel and the speed, only the turn signals would remain from the original dash that I'd need to retain. I wonder if there's a way of telling the computer that the turn signal is on....

Continuing down this mental thread, the space available for dash concepts: 13 or 14" across. 5" high. So, fitting a Jetta IV instrument panel (even if I wanted to) wouldn't fit. The one that came from the donor Beetle definitely wouldn't fit. Maybe a tablet could. A typical 7" Android is 19.2cm x 12cm -or- 7.559055" x 4.72441"

Perhaps, if oriented such that the thick "bottom" (or the far right end in the picture here) were set on the outer edges, we could support two screens for a dash.

Seeing that there really isn't an iOS comparable, I looked around for a cheap tablet. $40 gets you a bluetooth enabled, 4GB tablet (link). I couldn't use two of them without modifications to either the vent / heat controls or something else more drastic. Still, its an interesting mental exercise. Maybe it's worth only doing one, covering the blank spot where a tachometer should have been installed stock from the factory (Really VW?, Really?) and most of the speedometer, leaving the cluster with the fuel gauge, turn signals and idiot lights still visible. If the tablet can be easily removed and installed, I could pull the tablet out of the way at will, leaving the stock dash in place. I got one of these tablets just for laughs and the low price comes from the weak battery. Still, this is an interesting idea.

So, assuming the tablet isn't unattractive, how to get the engine computer to tell the tablet what's up? There are a surprising number of tools out there for this, actually. I went and bought this one from scantool. It came with free software for the tablet which I played around with a little bit.

For now, this stuff is sitting in a heap while I consider how I want to address the fuel tank level sender. Ultimately, the sender needs to be replaced, and it makes the most sense to just replace it with an original ohm-range sender. If I want to go further with the ECU stuff, I can do the fuel gauge wizard, build a hall-effect speed sensor and really jump into the electronic dash all while keeping the original functionality.

That's it for this week. Thanks, as always, for following along. With the holidays upon us, and family descending upon us, I may not have much time to post. I am taking some time off, so I'll have some time to generate content of course. I just may not get to telling the stories until some time in January. I appreciate your following, rare comments and more regular emailed thoughts and ideas. Please keep sharing.
Last, if you're in the Portland area and need a place to fix your daily, I'd be hapy to help. You can even use my driveway. Hapy Holidays and Hapy New Year-

Tuesday, December 12, 2017

Zup date

Its been a few weeks of sporadic work on the 280ZX we picked up in October. Today's post covers some of the work that's been done thus far.

When we bought the car, the owner was pretty up-front about the condition of the car. He had the transmission gone through, put in a new clutch and rebuilt the engine. My first thought when I heard that statement was "yeah, right". When we looked the engine bay over, though, the paint tells the story: the engine block has been recently painted purple. The exhaust, intake and all other components haven't any purple on them. So, either he went through considerable trouble to make it look like he rebuilt the engine or he actually did. He did share that the valves will need their post-rebuild adjusting, so we'll have to remember that.

Still, any used car probably has old fluids in it. With a recent rebuild, engines need oil changes more often, so one of the first things C did was an oil and oil filter change. Good man. The oil was not terribly black and we did not find any little metal bits in it. Even the magnetic drain plug was clean. All good signs.

Once the oil was done, C wanted to get after the bodywork. The front driver fender had a pretty good dent in it and the driver door was bad dented badly enough that it wouldn't close properly. The fender was extremely easy to remove. There is a series of bolts along the top, like any other car fender, but only a few on the bottom and none along the door frame. Stunned, we had the fender off in a matter of minutes. C thought about the cost of a replacement fender and decided that trying to get the dents out was a worthwhile learning experience. So, he grabbed a framing hammer, set the fender on an old tire and started wailing on the dents from the inside of the fender. Now, that sounds pretty horrible, but the execution was actually pretty damn good. He spent about an hour working the dents down smaller and smaller until all that's really left are framing hammer markings. We will need to finish the fender out with some real body tools, but I think for his purpose (daily driver) he will be able to get it looking decent.

The driver door was a bear to get off because of the dent. We needed to hammer and pry-bar the lip just so we could get a wrench onto the hinge bolts. Still, with a 12mm crescent, the 6 bolts came off with relative ease and the door was soon on the ground. We sourced a replacement outside Sacramento, but for now the driver door opening is protected with a tarp while the new door is stripped. As you can imagine, our front yard looks stunning.

As you could see in some of the pictures, the prior owner wanted the accent color to be purple rather than the stock blue. So, he painted all of the blue areas a plum color. It may have been great for him. C hated it. So, he went at it first with my angle grinder. It created lots of dust, but didn't really take out much of the purple. So, he bought some aircraft paint stripper. Now, this is some nasty stuff, but it totally worked. The key was letting a first coat of stripper set up and then put a second coat on. Once that's set up, we could strip it off. Some areas we did one coat to get the clear coat and a second pass to get all of the paint. Either way, C stripped all of the purple paint off: passenger fender, driver fender, passenger door, hood and even the little bits on the rear quarters.

That's as far as C (with a little help and guidance) has gotten. His progress has slowed as he has decided to get a job to help pay for things. Since school is his first job, and hourly wages for new-to-the-workforce jobs are rather low, the inflow of capital will be slow, so the rate of improvement to the 280ZX will reflect that.

Thanks, as always, for following along. If you happen to have a cache of 280ZX interior bits, we're looking for those too-

Tuesday, December 5, 2017

Oh Clutch.

Today's brief post covers the swift demise of the clutch in Flash, the 2001 TDI Jetta.

Full Yard
The stable of cars in my driveway and garage has steadily climbed over the last few years. During my humble beginnings with the ex, I had the '72 camperbus (Hapy) and a '01 Jetta TDI (Flash). I fixed whatever car she had along the way, but generally speaking, I have the car I drove and the bus I worked on. When I met Boo, her 2000 Saturn (Dude) was her daily driver. She has had the same mechanic for that car for years, so I pretty much don't touch it out of respect for their relationship. Between kids' cars: '01 Jetta Wagon TDI (unnamed), '87 Jeep Cherokee (Jaws) the '79 ZX (not named yet) and my extra project car (the oft-posted about MG), our yard and garage have 7 cars packed in. Of those, at least 3 are daily-driving: the old Jeep, an FR-S and Flash the Jetta. The most often used of them all has been Flash.

He is a real trooper. After re-doing the front suspension a couple of years ago (See: Daily Driving), and replacing his steering rack after Les Schwab failed to tighten the baffles during alignment (letting water in and fouling the rack), he's been very reliable. He has crossed over 200k miles and while the body has looked better and there are all kinds of little things that bug me, he runs great. At least until a couple of weeks ago.

Oh Clutch
A couple of weeks ago, something in the clutch pedal went "pank!" and a little hiccup could be felt about an inch above the floor when raising the pedal from fully depressed. The clutch had been slipping a little bit in first gear, and I had started hearing some noise when the pedal was depressed and engine at idle. So, I knew something was going. As I write this, I'm inclined to think it's the throw-out bearing, but a new one of those comes in the clutch kit and in order to replace it, you need to get that far in anyway, so I started thinking about the job. And then things went from screwy to un-drive-able. We had started driving the FRS more, and Flash had sit for a few days when the need arose for me to drive Flash to work. The clutch started acting weird almost from go. Everything was fine so long as I didn't depress the pedal, which sounds silly, but I knew I couldn't make it to the transit center and then home again so I aborted the drive and turned around. I got home, but he was banned from travel until I do the clutch job.

As I mentioned at the top, I have 7 cars littering my driveway and garage. The garage is officially a 2-car, but you really can't fit 2 cars in there, though there are 2 doors. Behind door #1 sits the MG, without a top. It can't move out since the steady fall rains have arrived. So, I will need to do the job similar to how I did the last front-end job on the Jetta (replacing the steering rack): with the rear-end sticking out the open door. I really don't like the idea of the garage being left unlocked like that, so this will take some extra planning. But first, parts need ordering, and I need to verify I have all the requisite tools.

I really don't prefer car parts from the NAPA or O'reilly's of the world. The parts for some cars are okay, but for the European imports, they generally aren't that great. Since Discount Import Parts (DIP) closed their Beaverton location, I'm effectively forced to buying online. Fortunately, TDI owners have a few in-community vendors like IDParts.com who offer OEM and better-than-stock parts.

I like the dual-mass flywheel in the Jetta, and am choosing to keep it rather than swap it out for a single-mass. There are lots of cheap "conversion kits", especially at the NAPA's, etc where you can get a clutch, pressure plate and flywheel for $200. Sounds too good to be true? It probably is. Especially when a good clutch and pressure plate (with throwout bearing, grease and an alignment tool) is close to double that. If you're gonna spend 6 hours tearing your car apart, put in a good part, right?

So, I ordered the dual-mass flywheel fitting clutch kit ($300+). I decided to get a new real main seal as well. These run around $35, and are the last line of defense between your engine oil and your clutch. When these leak, oil gets on your clutch, forcing a new clutch job. I have not yet decided if I will replace the seal. I just figured that having it in-hand could stave-off Murphy's Law.

Tempted Fate
I thought I was being smart getting the rear main seal. Maybe I was. Unfortunately, there is something more serious going on within my engine bay that has me stumped. I can't start the engine anymore, and the battery dies after a handful of attempts. Maybe the cheap NAPA-replacement alternator I put in had gone bad. Maybe the recently replaced battery failed prematurely. Maybe my starter failed. Maybe there's something more serious happening inside like the timing belt or injection pump skipped a tooth. I don't know. I can say, though, that I entertained thoughts of simply parting the car out and thinning the herd of cars by one. Since the Jetta Wagon doesn't currently work (bad automatic transmission), now I got thinking of combining those problems: I take the working transmission and all the other manual transmission bits out of Flash, combine them with the new clutch kit into the Jetta Wagon and part out the rest of Flash.

And then I was able to get him started. It required a boost from my charger, but he started and I was able to back him up a few feet. Sweetness, the engine is fine. It's a pure primary electrical issue: battery, starter or alternator or a combination. A couple of days after I moved him, I tried to start him again. No start and the clutch pedal wouldn't return back up by itself. Neat.

Projects Pile
I'm increasingly loath to look out my front window at a growing list of broken things needing repair. Hapy needs a radiator. MGB needs a top. 280ZX needs a door and an interior. Dude needs a headliner. Jetta Wagon needs a transmission or a 5-speed swap. Jaws (the Jeep) and the FRS are the only consistent cars and Jaws' transmission is starting to go. Clearly, I'll have plenty of material for the blog. It's just a question of when I'll have the time to do the work.

The forces at work these days (holidays, boys need my time, icy weather approaching) have led me to the decision to take the clutch kit and Flash to the local clutch place to do the work. I can't drive him in his current condition, so I'll just haul him over there. I'll get the battery checked first (pretty sure this is it since an overnight on the charger doesn't get enough juice in there for the engine to start), but if it's the alternator, I'll need to do that replacement after the clutch is done. Since the clutch job requires the removal and re-install of a starter, I sent a replacement starter (from Discount Import Parts, so it's not crap) with the clutch kit and Flash. It is actively getting worked on, so if things go well, I'll be driving him home tonight.

UPDATE (2017-12-10): the no-start issue was resolved by replacing the starter. The new clutch is so easy to depress, the gears engage nicely and he starts right up. The Clutch Doctor did an awesome job and Flash is back to being our daily driver, shifting the FRS back to occasional use.

Thanks for following along, and I'll have something with pictures next time :)