RE: 1997 A4 1.8T Quattro rough idle problem
 

I tried testing both my old Huco and new Bosch ICMs following the exact steps above, but there was no resistance reading when I touched the + dmm probe directly across from my clamp. I tried various resistance ranges and still no reading. I have no idea if I was doing something wrong, but I'm pretty sure I had it set up right. I had the neg. probe touching the center pin on the 5-pin side, with the speaker wire wrapped around it going to the neg. side of the battery. I had the wire from the pos. end of the battery (with a clamp on the end) attached to one of the other 4 pins on the 5-pin side, and the pos. probe touching directly across. Let me know if that sounds right. The directions were pretty simple and I thought it would work but gave up after a couple hours of not getting any readings.

RE: 1997 A4 1.8T Quattro rough idle problem
 

well, that sounds right, what did it show on the meter? Did you have the meter set correctly, and the leads plugged in to the right spot?
what kind of battery did you use, and did you test it first?
Maybe the ICMs are bad if there's no continuity. But did any of them read correctly?

RE: 1997 A4 1.8T Quattro rough idle problem
 

Ok just tested my old Huco again. I used a 1.5 volt AA battery. Tested the voltage first like the directions (from robsaudiworld)said and I get a reading of about 1.6 volts, so the battery's fine. Then I tested the resistance for each matching pin on the ICM:
-Wire attached to neg. end of battery wrapped around neg DMM probe, attached to middle pin on 5-pin side
-Wire attached to pos end of batteryclamped ontoone of the other pins other than the middle on the 5-pin side
-Pos DMM probe touching the pin directly across from the speaker clamp
I get a resistance reading of 1 (open) for every pin. In the guy's example it looked like only one of his pairs of pins was open, the others gave a resistance of around 300 ohms. Isit possible that both my old ICM and brand new Bosch ICM are completely f'ed up? I wish I had another one to test but I dunno if I want to drop another $100 justto see. I'm gonna go get the Bosch out of my car and try testing that one again. Fun times haha.

RE: 1997 A4 1.8T Quattro rough idle problem
 

Ok, just tested the my Bosch ICU(0 227 100 211) and same result. Reading of 1 (open) for every pair of pins I test. Afraid of buying another one if I'm doing this test wrong, but if I'm doing it right and it's f'ed up, I'll contact the place that sent me this one and say it's defective, I think there's a 30 day warranty, hope I didn't buy it more than 30 days ago. Here's a picture of how I set it up for one of the pair of pins tests (took it with my gf's camera, kinda blurry sorry), let me know if it looks right:
http://i33.photobucket.com/albums/d5...S/SUC50080.jpg

RE: 1997 A4 1.8T Quattro rough idle problem
 

I just read something online about someone having a bad ECU chip solder blowinga fewICMs. I wonder if my old ECU could have blown my new Bosch ICM as soon as I plugged it in and turned on the car. I didn't test the Bosch ICM when I first got it, I just plugged it in and tried it. That would suck. I'm gonna try cleaning the throttle body today anyway though, since the original turbo that was blown was due to previous owner using bad oil causing engine sludge. There's probably some buildup, so it'd be good to try.

RE: 1997 A4 1.8T Quattro rough idle problem
 

Well, it sure looks like you did everything right.
Istll think your ICM is blown.
Buy a new one, and run the test on it first, maybe the old ecu did blow it.
The fact that the coils are good in other cylinders, really points toa bad icm.
But, if all the icm ports were dead, I dont think your car would run.
If your getting spark in the other cylinders, then some of them must be working. But maybe the way it blew is letting some work, IDK, I am not an electronics expert.
You should get at least one or two ports that have the 270-300 ohm resistance. Are you sure your meter was on the right setting, the 2k? My ohm meter and my car are not here right now, or id run the test again myself just to give you more feedback.
Maybe I can tomorrow.
Clean the TB anyway, it wont hurt anything, and you'll run a little smoother once you get it all worked out.

RE: 1997 A4 1.8T Quattro rough idle problem
 

Alright, cleaned out the throttle body yesterday so its all nice and shiny. Just have one more screw to screw back in since I had to quit early working on it. I ordered a Huco ICM today since it's a bit cheaper so I should get that in a few days. I'll run the resistance test again and hopefully get correct readings, and if so, plug it in and do some drivin. My new ECU hasn't thrown any weird codes so I don't think the new ICM should be in danger of blowing unless something else could blow it. I think I'll test it before and after a test drive, and if it gives me good readings before, hopefully it will after too, and not be blown. I'll post again once I do all that. Till then I'll keep ridin the bus to work, hangin with the hobos haha.

RE: 1997 A4 1.8T Quattro rough idle problem
 

I have a 2000 1.8TQM that has the EXACT same idle problem fro the sounds of it. . .

I have read the engine codes and i get about the same, the cylinder 1 misfire, the general misfire code as well as a "fuel system running to lean"

I am VERY curious to find out what the cause of yours is! Might be an easy way to figure out what is faulty with mine as well!

Look forward to your response

RE: 1997 A4 1.8T Quattro rough idle problem
 

Fizzle-fer-shizle,

Your car is a little different than his, he's non-drive by wire, where yours is DBW, and your car does not have an Ignition control module, which is probably his problem.

Yours on the other hand, sounds like a bad coil pack. Try swapping some of your coil packs around, and see if the misfire follows the coilpack to the new cylinder. If it does, repalce that coil pack.

RE: 1997 A4 1.8T Quattro rough idle problem
 

Bad coilpack would likely cause the car to run like shite at all times... flashing CEL's and the like.
Too lean and a rough idle could definitely be a MAF problem.