The Project Pad

PRY4SNO wrote:Good tip about swapping those fuses and relays. Nice to know exactly which ones to target.

IIRC the FP relay trick people use supplies 12.5v all the time, so 11v should be sufficient.

I wanted to throw that in there in case I ever needed to refer back to it in the future. Also a good thing to know if your relay goes bad and you don’t have a spare.

After installing the new speed sensor, I went to try and start it and wasn’t getting any spark. So I had to start over with some checks. Looks like I have another bad hall sensor. Tested it via the workshop manual method and off the car too. With 12v supplied to the sensor, not getting any voltage across terminals 1 & 2 of the hall sensor as the window passes by. Ugh! This this is wearing my patience.

https://youtu.be/b8FIcLgOKV0

Are new hall sensors available? If so, can they be installed by a DIYer?

They we're available as of last year. I haven't looked in a while though. As for installing it, you need to pull the shaft out to do it.

I found this link to a DIY guide. Although it’s for an early AAN with the tuna can distributor, it says it applies to the 7A as well.

https://12v.org/urs/Replacement%20%20of ... ibutor.pdf

Looks correct to me. Now, finding the sensor.

According to this post on Facebook, Bosch 1237031296 can be used but it’s 180 degrees out. I guess due to its design. Looks different from the original where the plug and sensor are across from each other.

https://www.facebook.com/groups/SmallCh ... 028777734/

https://www.amazon.com/dp/B001CO18IQ/re ... ACbXSBP8ZC

I might give it a try.

I ordered that hall sensor and started disassembling the distributor today. The pin that holds the gear on the shaft can be a bitch to remove. The flared end has to be ground down before it can be punched out. And punching it out required some heat and heavy pounding.

Got the sensor in today and fitted it to the distributor. It showed up sooner than expected, so I need to go to the hardware store and get a 4mm roll pin for the gear.

Well, it seems that most people that have used that style sensor did so on an early AAN with a tuna can style cam sensor or a 3B/7A that is on stand-alone and converted to COP.

I realized I may not have thought this through completely. If we were dealing with a 4 or 6 cylinder, it would work, but there isn’t a corresponding wire terminal that is exactly 180* across from what is normally number 1. Doh! Look like I’ll be returning that sensor.

I have this one on order, but it’s a little more expensive.

Bosch 1237031292 Timing Module https://www.amazon.com/dp/B001COAMLA/re ... BCbGVM062K

Got the distributor back together with a new sensor, cap and rotor and installed it on the car. Also replaced the ignition reference sensor. Was still not starting. While testing for power at the distributor, the positive wire gave up by breaking off at the terminal. So, I repaired that...still no start. Back to testing for power at the distributor and I wasn’t getting 12v across the plug. I was getting 12v from the positive wire to engine ground.

So, I got looking for wiring issues between the distributor plug and the ECU. Everything looked fine. I plug the ECU back in and check the distributor plug again and I was getting a nice steady 12v across the plug. I thought, I better try to fire it up. Sure enough, it started right up like it should. It scared the crap out of me because I wasn’t expecting it to start and there’s no exhaust after the header.

It’s been started several times since. I’m not confident that my troubles are behind me yet, but at least it’s running! Pretty sure there’s something wrong with the distributor ground wire.





https://youtu.be/RsyZIHyfZiM

These old cars can be a love (hate) affair.

When I rebuilt my black UrS4 it had been together and ready to go for about a month but would not fire up. Was renting a garage so had to have it flat decked to a friend's garage when the lease was up. Not long after I found out I had installed an extra ground from the passenger side of the block to the motor mount bracket... would have never guessed an extra ground would prevent it from starting. But once I removed the second ground wire, she fired right up and never had another issue like that again. Frustrating while you're chasing down every little thing, but oh so satisfying when you get it.

Plus now you have some new parts, and some (probably good) spares to either sell or keep just in case.

PRY4SNO wrote:These old cars can be a love (hate) affair.

When I rebuilt my black UrS4 it had been together and ready to go for about a month but would not fire up. Was renting a garage so had to have it flat decked to a friend's garage when the lease was up. Not long after I found out I had installed an extra ground from the passenger side of the block to the motor mount bracket... would have never guessed an extra ground would prevent it from starting. But once I removed the second ground wire, she fired right up and never had another issue like that again. Frustrating while you're chasing down every little thing, but oh so satisfying when you get it.

Plus now you have some new parts, and some (probably good) spares to either sell or keep just in case.

I was starting to question why I bought it back. lol

That extra ground would be hard to track down.

I’ve tried to not shotgun parts at it which has caused me to think some parts were okay when they really weren’t. I do think it needed the ignition reference and engine speed sensors. They were both low on ohm checks. I don’t think anything was wrong with the hall sensor, but I can throw that sensor in another distributor, but I would need a new gear since it had a plastic gear.

I hope to move towards re-assembling everything and getting it on the road.

Took her for a trip around the block. Only took 6 months to get her to move under her own power. lol

Great news! That's a big step!

Nice job troubleshooting .
I have deal with a few projects with bugs like this and while it takes a ton of my time I feel like I know the car and how it works much better after .

Afterthought wrote:Nice job troubleshooting .
I have deal with a few projects with bugs like this and while it takes a ton of my time I feel like I know the car and how it works much better after .

I agree.

DE80q wrote:Great news! That's a big step!

I appreciate everyone that helped me troubleshoot the issues.

Awesome!!

That's the ticket!

Just in time to celebrate getting the coupe back on the road, I found my long-term swap solution...lol. Wish I had found it first, but that's how it goes sometimes. I learned a lot with my first swap. It's completely stock, from what I can tell, but I'm no expert. I have access to just about anything else on the car too, so I figure I'll also grab the engine harness, ECU, anything else touching the engine. I might grab the fuse box too, since mine has some questionable fuse terminals. @Grillage suggested I grab the radiator fan/shroud also. Anything else I should grab? The ersatz S2 page lists a whole bunch of stuff I'll try to get also.

Once I get this 3B home, I'll slowly start cleaning it up and planning for the conversion, but I'm not in a big hurry now that she's running.

I don’t think you need the shroud from the 200 - get one from an Rs2 from Audi tradition. You just need the fan

This is awesome! Good luck

Nice find! Probably better to find it after the car is running, so you can take your time and still enjoy 5cyl noises.

Grillage wrote:I don’t think you need the shroud from the 200 - get one from an Rs2 from Audi tradition. You just need the fan

This is awesome! Good luck

Don't forget the associated relay.

Yeah the fan works with the AT shroud, that’s what I run ,
Side note does that fan have resistors associated with it that are mounted next to the fan in the car ? You might grab those too.
I was having trouble with my 200 fan/AT shroud setup in the urq- when it kicks on and goes from off to full speed and draws too much on the system . Its actually enough to cut out the fuel pump momentarily .
I would take basically everything in the engine bay , I mean depending on the harness and tuning you’re planning to run I’d take the factory engine harness too if possible .

I’ll have to check on the resistors, but if it has it, I’ll get it. Only problem with the donor is, it’s currently at my friends place an hour and a half away. Not easy to go out and check on something.

For what it's worth, the resistor is bolted to the frame rail just ahead of the radiator.

Thanks.

Like I mentioned, the donor is at my friends (czd3my over on MG) place. He enjoys this stuff and made quick work of removing the 3B for me. Got a pic from him today, he’s already pulled the engine, engine harness, ECU, fuse panel, fuse panel harness, down pipe, altitude sensor, airbox, intercooler and piping, radiator fan, and some other stuff too, I’m sure.



From what I remember reading on other project threads, I think I need one or both of the 3B’s fuel lines. Correct?