Stupid car. Need some help/ideas.

[Tifun]

I got stranded on the highway today, of all places to get stuck, it had to be one of the busiest in the area. Lots of old ladies giving me the bird.

Car is missing, and missing very very hard. cly 3 according to the reader. I put new coil packs in this week, no fix. I have new plugs as well. All plugs have been changed as well, they even look fine.

The car has been having a miss. It started off for a second, then cleared up, then a little longer before it went away, and so on. Now....it's misfire all the time. I've swapped the packs around and still have the misfire. Same with the plugs. I even rechecked the gap.

I don't know what else to check. All my search keeps bringing me back to coil packs, which are new, and have been swapped around to still give me the same cylinder miss. I guess I have two options right now in my mind that I can do unless someone else has a solid idea.

1. Check harness for cracks/exposure/wear

2. Compression test all cylinders



Could this possibly be a headgasket going out on me? I've hd them go before, but never with signs like this. The only other thing I can think of is checking the coilpack harness for damage. Has this been as issue with anyone?? I've not seen anything that say yes.


So....give me ideas of what else I could be looking at that I might be missing.

-Keith

[Ben Franklin]

if you have a compression tester, take one plug out at a time and screw the hose into the spark plug hole, next take the cap off your coolant bottle and then blow compressed air into the hose from the compression tester

if you see bubbles in the coolant bottle, then its safe to say you have a bad head gasket

[shaggyt]

i think it's because your car doesn't like to be called stupid.

[geeky]

do you have access to an ignition scope?

[Tifun]

if you have a compression tester, take one plug out at a time and screw the hose into the spark plug hole, next take the cap off your coolant bottle and then blow compressed air into the hose from the compression tester

if you see bubbles in the coolant bottle, then its safe to say you have a bad head gasket

I've never done it that way. I've always done it with cranking the engine.

Anybody else use this trick?

[Tifun]

do you have access to an ignition scope?

I have vagcom. It's showing misfire cylinder 3. P0303.

[flynnr]

MAF

[tdn]

ICM

[B5A4Kevin]

you can do a compression test (cranking engine), or you can do a leak down test (pump air into engine at tdc combustion stage and listen for an air leak:intake or exhaust manifold, crank case breather, coolant reservoir)

when you pulled your plugs, was the misfiring cylinders spark plug wet with fuel?

you may need to swap injectors around or use a noid light. you can also get 4 glass or sturdy plastic cups pull the rail, and put each injector in a cup and crank the engine, to see if you have more or less fuel in the misfiring cylinder.

are there any new faults?

[tdn]

MAF

If it were his MAF, I don't think it wouldn't just be misfiring on cylinder 3.

[Tifun]

K swapped injectors. Still number 3. I'm leaning towards PCM at this point. But I need to do the compression test first. If I can find the damn tool.

[baboom]

how about icm its a common problem..

[akielb]

Switch the coil packs around if the missfire follows, then you've got a bad coil pack. If it says at Cyl 3 then replace the ICM

[99blueb5]

my vote is the ICM its pretty common with a 1 cyl missfire and that hasn't been consistent

[djwimbo]

The ICM will 99% of the time cause a consistent misfire on cyl #3 only.

If the misfire didn't move with the injector/s and you have decent compression, I would go after that ICM. Like you said, after you swapped the coils it was "running like a top". That makes me think it isn't a compression issue.

Then again, things always seem to make the most power right before they blow up ... knock on wood

[Tifun]

couldn't find my compression tester last night. So I'll be picking up a new one today. After that check I only have the ICM. All the wiring seems good. No visable cracks in the insulation. And again for those who haven't read the whole OP. I've swapped coils out multiple times.

Is there a way to scope the ICM via vagcom? I looked around on rosstech and didn't find what I was looking for.

Also since I don't have my other car road worthy yet, I had to drive the a4 this morning. It didn't misfire the whole 30 miles. This is driving my patience and pocket book LOL.

[stilldubbin203]

i dont believe theres a way to check it on vag com...i know you can physically check it by checking the resistance across each leg of power but i forget what the readings should be. Mine just went and was doing the exact same thing.... you can open it up (very carefully) and see if any of the connections are broken inside. That would be a good indicator of a bad ICM.

[Poopie]

its probably the ICM. or you could have lost compression on cyl 3

[flynnr]

If it were his MAF, I don't think it wouldn't just be misfiring on cylinder 3.

yeah idk really, but my buddy with a 1.8t got a cylinder 2 misfire code and he couldnt even hardly run his car for more than a minute. the guy at evolution street and performance swapped out his maf and a coilpack and he was good to go.

could be totally different scenarios i guess but sounds similar enough, who knows

[Jkilla71]

My vote is the ICM...mine gave me cyl 2 misfire code. My ICM went bad at 60k. Do a search... someone has a DIY how to test the ICM output with a meter

[pipe7284]

ICM

[Tifun]

Ok, compression test is good. They were all within a pound of each other. Thank god, I don't feel like tackling that battle until we get our house. On the other spectrum, I am going to ohm out the ICM, I didn't think about it before I left work so I have to run back out tomorrow to pick up my meter and megger. I can meg each input to check the quality of the resistance. Probably half to do it in the lowest voltage the megger will go. Anyway, that will let me know for sure if the is a potential ground fault.

Other tha that, is there a difference between years for the ICM? I have a 99.5....Just trying to get all my apples in one barrel so I don't waste any more money. This is just slowing down my Corrado project with each purchase.

[Tifun]

Other tha that, is there a difference between years for the ICM? I have a 99.5....Just trying to get all my apples in one barrel so I don't waste any more money.

Anyone? I see a ton on ebay.....engine is an AEB.....One place told me there was a difference, but all the ebay crap shows them to fit all the 1.8t's. Is it the same as the 1.8t from lets say an 03 GTi 1.8t?

[BluMagic]

i got one on ebay for $60

[Tifun]

i got one on ebay for $60

Is your car a 99.5?

[turbo kraut]

i wouldn't say that it would work off an 03, but call a vw dealer..... they will check your vin and can tell you if they can get a icm to work for you


that is what i did with my maf......saved about 150 v audi maf

[somebody5788]

GL man hope you get it fixed soon! How'd you end up towing it? Why didn't you get the road side assistance on your iPhone! Would have saved you some sweat haha.

[biketsai]

BTW- I dont think they had ICMs on the newer motors, seems to me like it was the AEB. Dont quote me on that, but I know that the 00-01+ all have MAF's iwth no ICM

[Tifun]

GL man hope you get it fixed soon! How'd you end up towing it? Why didn't you get the road side assistance on your iPhone! Would have saved you some sweat haha.

Yeah no kidding. Kicking myself in the ass now for not get the roadside assist lol. I limp partway, then a buddy went to get a tow dolly, found out that wouldn't work, then a buddy went over to his dads to get a trailer, got that came and got me. Eventually got the car loaded on cline ave(known as cline international speedway) it's one of those roads where you see the cop video of the guy vering of and smashing, himm, his car, and the drunk guy he pulled over. It's one of those highwat with no real shoulders and you get passed regularly while cruising at 80-90mph(not exagerating.) Needless to say I had a puckered butthole for about an hour and a half, plus I was cold because I couldn't run the car for heat lol. All in all, I would recomend this event to others.

BTW- I dont think they had ICMs on the newer motors, seems to me like it was the AEB. Dont quote me on that, but I know that the 00-01+ all have MAF's iwth no ICM

That's interesting. I figured regardless they all had icm's. Unless the ecu could somehow control the spark.

[Poopie]

only the aebs has ICM. they should all work. I think the huco brand or whatever has the best reliability

[djwimbo]

That's interesting. I figured regardless they all had icm's. Unless the ecu could somehow control the spark.

ECU's control spark regardless. Audi is one of the first companies to use the Coil On Plug design, and at the time they needed to use an ICM to control spark efficiently. That's why the ME7 cars don't need an ICM, and for the old school guys like you and me, we get an ICM.

If you think your ECU isn't controlling spark, then tell me how it knows when to pull timing.

[Tifun]

If you think your ECU isn't controlling spark, then tell me how it knows when to pull timing.

Through sensors exterior of the ecu that send the reading to the ecu. Just like the icm itself regulates the spark. I view the ecu simply as a gathering point of sensor data or a hub if you will. At that point the ecu can determine what gets pulled/added. But first and foremost. Those readings still come exterior of the ecu before communicating back to the mother ship haha.

[turbo kraut]

unless you have a motor from i think an 00 or newer you will have an icm


i thought once they changed the "design" went to the 170 motor, that is when they got rid of the icm

[Mawhitey]

ICM

+2

[FknChizA4]

when ur car misfires does it kinda shake and sounds wierd??? if so it might be your ignition module.. that piece of shit cost me 1100.. changed everything from coil pack to plugs, hoses, then i got an after market ignition module n it broke down 3 months later.. make sure if that is the prob get a Bosh... Ignition module