Its already in the "Good links" sticky at the top of the page.

 

Are the A4 1.8quattros, good cars, or are they full of problems?

 

wow, i'm not going to justify that question with an answer.

 

That's like asking an alcoholic if beer is good!

 

Good Find.

 

I am currently working thru a misfire problem, Car is completely standard 97 1.8T 150,000 miles

Code says no. 3 is misfiring, plug does not look like itis firing at all.

I have replaced the plugs and the coil pack,

Moved the coil pack as well but problem remains on 3.
Have done a compression check, cylinder is OK,

tried pluging spare Ignition pack to harness and using spare spark plug to check for spark no signs but not sure if test is valid (does the pack need to earth - or is the reath in the wire sufficent)

Next guess is the ignition control module, just a bit reluctant to change parts wholesale, have already bought plugs and a coil pack, plus software and a USB to obd II convertor. Any thoughts on what else it could be - before I buy an Ignition Control Unit or take it to Audi

 

You need a ground still. The engine acts as a ground when the plug is in the cylinder. You can get a misfire from a dirty or inoperativeinjector also. I would also try injector cleaner. Does it misfire all through the rpm range, down low or up high?

 

thru the range, spark plug was earthed on the head, was more interested in the low voltage side earth. Because I figured if the plug did not have an earth I (or my mate who was holding it) would have at least got a high voltage tingle.

Problem happened all of a sudden, went to a shop, parked the car, came out started it and it imediately ran rough and MIL came on. It has not cleared since, plug is wet so some fuel is getting in.

Not sure how you clean injectors, or whether you just replace them.

 

Injector cleaner but it sounds like the injector is firing (since you say the plug is wet and it misfires through the whole rpm band). Sounds like you need to check voltage into the coil to see if you have power if you do run a leak down test, not a compression test to see if you have a slight leak not enough to throw off a compression test, if you don't have power at the connector to the coil check the volage higher up stream like at the ignition control modual, if you have power there it is the wire and if you don't it would be the control modual. Otherwise I would have no clue what is wrong.

 

$50 says its the ICM