Erik Myers

Hey TEF,
Thanks for the details on the windows, that's super helpful. I have a 3-D printer, so I think I'm actually gonna 3-D print the new guides and such for the window motor. I picked up some 1/16" cable from Ace, that's the size to use. Unfortunately the windows are on hold until I can get the motor running right again. BUT:

Motor Update:
So, I took the exhuast from the manifold back off. It was bad. like, BAD bad. World War II flashbacks bad. Look at this atrocity:


Terrible attempt at a patch job


The hanger over the final drive had come loose, and let the pipe rub a GIANT hole through against the axle shafts.


The primary muffler. I'm afraid it was just too gone to save. I cut it open because it sounded like a maraca in there. Turns out to be a rust pile.


Note the excellent beer can patch on the cat hookup. \


A Miller High Life; The Champagne of Beers. Only the best for this car.


Looks like we had some trouble getting the O2 sensor out so we just gave up and cut the wire. Nice. The cat was also 100% clogged to death.

This poor, poor car. I feel like I rescued an abused child from the hands of an alcoholic. Anyways, I had to remove the primary muffler, it was just too far gone. I replaced it with an inline glasspack. I also welded the beer can patch job back and patched all the holes with my TIG welder and some cut pipe pieces. It looked SO much better:



The glasspack in line. Note the welded patch to the beercan. I installed this back in line. It fits great and actually sounds way quieter than before.

I reinstalled this repaired pipe, and it sounds really good. it's actually a little too quiet. I ordered a nice simple single exhaust tip. I think I'm gonna straightpipe the rear muffler and cut that crappy looking dual split exhaust tip off. I think a single straight chrome tip will look better, and the glasspack only will help the sound. I also punched the Cat out, but the hollow chamber results in some pretty obnoxious high-frequency noises. I think I'm gonna go back and cut the Cat out and straight pipe that, too (my county doesn't require ANY kinds of emissions inspections. Lucky me!).

With the exhaust gutted, I feel like I really actually did free up some air flow. The engine runs much smoother now, but the issues is still there. At this point, my cap out limit is right at 4000 RPM's, but I've definitely identified the problem. When I look at the timing for the car, it's right on factory at idle speeds (roughly 800 RPM's). However, if I rev the engine, the timing starts to lag, BAD. I believe there could be two causes for this: The distributor pickup coil is jacked up. The pickup coil looks like this:


The coil I ordered from Amazon for like $80

On MY coil, that black wire is totally stripped out, and the black female plug end is totally jacked up too. Apparently this is a device that is used to help the timing advancement (Or at least spark time optimization). I think mine is not working properly. There is also a vacuum assembly on the side of the distributor. From what I can tell, that's the MAIN timing advancement mechanism. I need to figure out how to test it. Obviously something in the timing isn't working right, because my timing is lagging BAD. And that makes sense. The problem isn't cylinder specific (Which explains why it doesn't matter which plug I pulled when I was testing compression, because the problem is for all plugs). This basically creases a power blocking wall. The engine is more than capable of putting out more power, shoot it could probably hit 4000 RPM's under no load with only a few cylinders firing. This also explains the sudden abrupt power lack and the backfiring. The car just can't get past 4000 because at that point the timing is lagging behind so bad that the exhaust valve has already let the pressure off by the time it sparks. I NEED to fix the timing lag. We do that, we're golden people. The parts come in Monday (Darn this national holiday). I'll keep you guys posted when I pop that new coil in and try to troubleshoot the timing advancement vacuum assembly. Wish me luck. Cheers.

Erik Myers

Hey guys,
Iv'e had some time to look over quite a few more things on the quattro. The Hall sensor came in, so I popped the dizzy out and man, it was ROUGH. the old Hall sensor was actually rusted in place:


This thing was totally shot. Little pieces were rattling around in the dizzy.

I installed the new one and it looks pretty good now, it actuates freely with the vacuum assist now.


I'm still trying to diagnose the power problem. It's STILL there, ugh. I'm going to test all of the fuel delivery compensation pieces soon (Cold start vale, Auxiliary air device, etc). I feel like it's definitely a fuel delivery issue, it feels like the car is either rich or super lean, it seems to gurgle if I lay on the throttle too much around 3K. The problem is 100% temperature related. The car runs fine at cold temps and then runs like crap at high temps. Although, it seems like it does fine until I try to actually drive it. It looks like my car is definitely missing the Warm-up regulator:


So from what I can tell the warm-up regulator is supposed to automatically rich the mixture when the engine is cold and lean it out when the engine is hot? Could this be the culprit? I think the plugged vacuum line coming from the intake manifold was definitely supposed to hook up to the regulator.

SO my question is: The car seems to be running lean or rich after it gets a little heated up (Although it seems to redline ok if there is no load on the engine). Could this all be caused by a missing warm up regulator? I've considered buying one, but they're expensive. I'm also concerned because I'm missing everything, but the Haynes manual also shows this little thing attached to the side of the warm up regulator and I don't think they come with that if you buy them. I'm also not sure where you hook up the fuel lines to it, as it doesn't appear to have any unused fuel line ports on the CIS unit:


The Haynes manual showing some auxiliary device next to the warm-up regulator. I don't know if this is something I can actually buy or even need to.

SO is this issue really fuel related? It feels like the engine gurgles or chokes at 3000 RPM's, I wonder if this is a fuel or air problem? I don't see anything else it could be.
Would it be possible to correct this rich mixture problem with the CO screw? I know everyone says to stay away from that, but I feel as though an adjustment might actually be needed now that I've ruled out everything else. Let me know what you guys think.

Oh, I also replaced the O2 sensor and reset the OXS light, just for kicks. There's an unused two prong connector near the O2 sensor that's just dangling there. Could this be what was supposed to attach to the Warm-Up Regulator??
My "Coolant Temp" light is always on. I think the sensor is bad, but the gauge works fine. I also fixed the radiator fan, so it comes on as needed now. It turned out to be dirty connections on the coolant thermo switch.

Let me know what you guys are feeling I should try next. I think its definitely a fuel or air delivery problem. To sum up the thread:
1) I think the engine is supposed to be adjusting he mixture automatically after it warms up, but it isn't. Unfortunately thee are so many switches and auxiliary components to help the cold start that I can't really be sure if that's the problem right now. I'm wondering if a quick adjustment of the CO screw could help remedy this problem (Go ahead and lean the mixture out to make running at high RPM's better).

Here's a video of the car idling in my driveway. At this point it was already super warmed up, so the choking problem at 3000 RPM's was very prevalent. Listen close and you can hear it gurgle. Tell me your thoughts. Cheers

Rogviler

By the time the 4kq came along they no longer used a warm-up regulator (or control pressure regulator, CPR, as it's more often called in Bosch literature), although the block still had the spot where they used to go. Instead of that they moved to an electronic system stuck to the side of the fuel distributor. I prefer the CPR as it's a lot easier to deal with something mechanical I think.

The extra wires for the O2 sensor are to connect a meter to measure the AFR, basically. I understand you can use an analog multimeter (with a needle rather than an LCD display) to do this.

At any rate, you don't need to worry about that stuff. But it sounds like you're chasing phantom tails like me. I was sure the completely broken plug wires were the problem. Replaced them, still the same. That's how it goes. I think when one of us figures it out it'll be the same answer for the other.

I'm going to grab a new thermo time switch and see what that does. Mine is definitely temp related as well. I can't even drive it now that it's 90+ outside, it just runs too poorly. The part number is 0280130219 or you can get it from Autozone under the number SU5176. I'm not super convinced that they go bad easily, but they are fairly cheap.

Your coolant temp light could be a bad sensor in the coolant tank. I keep mine unplugged for the same reason.

-Rog

Erik Myers

Rog,
thanks for the input, that clears up alot of questions for me. I think I may have had an epiphany: so there are two temp plugs on the main coolant hose, right ? One on top of it and on on the bottom. The top one is the Thermo time switch, which according to Haynes controls how long the cold start valve is open. However, what's the bottom one for?! The temp gauge plug is underneath the coolant overflow, right? Which means we have this mystery plug on the underside (I originally thought there were only two but now there's this third one). So... Out of curiosity, I decided to cool crank the audi. I let it run for about 15~20 seconds (longer than the cold start valve would ever be open in 75°F weather) and it was idling fine at about 1100 RPMs. Then, I took a screwdriver and popped that lower plug wire off, and boom, the engine started running like crap. I think that might be a wire that controls the frequency module on the CIS. And I think that sensor is supposed to "open" the circuit once the engine gets heated up all the way, thus adjuating the AFR. However, mine might be broken, resulting in no change. That means that while the car is cold, it mixes fine, and it can redline. However once the car warms up, the AFR is SUPPOSED to change, but that sensor never clicks open. I'm gonna try warming the car up tomorrow then pulling that plug and seeing if that changes anything. It HAS to be heat related, 1000000000%. It's the only explanation for the greet cold starts but power loss after warmup.

Rogviler

You're on the right track, but the bottom plug is indeed the thermo-time switch. I had the same result when I unplugged mine. The top plug is the temp gauge and the plug on the coolant reservoir is for the level sensor, which usually goes bad and causes the temp light to be on all the time. No harm in unplugging that one, unless you're inattentive and might let your coolant get low. But with it bad you'd never know anyway.

While I was thinking about it I went ahead and ordered a new thermo-time switch, so I'll report if that does anything.

-Rog

Erik Myers

Dang it. Well that blows. I guess I'll order a new level sensor so my light will turn off (I HATE lights). Besides that I'm almost to the end of my rope here. That CO screw is looking mighty fine. Does that screw actually adjust the rate at which the plunger goes up as the metering flap goes up? Because trying to figure out all the ways I could possibly be getting leaned out/too rich. Although that doesn't make sense to be a heat related problem. I can't think of what else would be heat related.

Rogviler

Is your mixture screw accessible? It should have an aluminum plug where older cars have a hole. If it's been drilled out then that means someone has messed with it (which you generally don't need to do with CIS-E as it's within the scope of the ECU). I would leave it alone unless it has been drilled and fiddled with, but then you'll have to have the proper equipment to measure what you're doing, such as a wideband gauge, and you'll have to make sure everything else absolutely works as it should.

-Rog

Erik Myers

Rog,
by mixture screw do you mean the CO screw? I didn't have to take any kind of plug or cap out of the way in order to access it with a 3mm wrench. I didnt mess with it, i just tested to see if i could actually get to it. does that mean it's been screwed up? Cheers

Rogviler

Interesting. I'm pretty sure, though not positive, that all CIS-E fuel distributors had the hole plugged somewhat permanently. You can either drill it out or pull/punch it out, so it's entirely possible that someone did that and messed with it in order to get it to run correctly. In that case you may have already fixed what was wrong with the car but it's running poorly because of that adjustment being off. If you do play with it, be sure to take note of where you started and return it there if nothing changes. But I would only do that as an experiment, as you can easily make things worse. Clockwise is more fuel, counter-clockwise is less.

I have an Audi Fox with a CIS basic system that I put together myself, and it relies on that adjustment to run properly depending on if it's summer or winter, so it is possible to affect how the engine runs in that way. But like I said, be careful. I know that car really well and also have a wideband setup on it, so I don't have any issues.

-Rog

Erik Myers

Rog, sweet deal, I'll take a look at it. I may just see what happens if I rotate it like 180°, it really does feel like it a mixture issue (too rich/lean) but as to if it's actually that screw or not has not been determined I'll update with results tomorrow