I'll try and keep this short and sweet, but I need some help ASAP.

Last weekend I thought I fouled out a spark plug on my '99.5 Audi A4 1.8T Quattro. I pulled all the plugs and replaced them (they definitely needed replaced). The "check engine" light stilled flashed and the car was still only firing on 3 cylinders. I ordered an ignition coil and put it in tonight. I started the car and pulled the coils till I found the one that didn't change the idle soI knew it wasn't getting spark to the plug. I put the new one in and it still didn't make a difference and wasn't getting spark to the coil or plug. I really don't know where to go next. I know that it is one cylinder that isn't firing. I also know that it isn't the spark plugs or the ignition coil. What could it be and can I fix it or do I have to take it in? I looked and saw that the wires from the coils go to the ECU (I think). Now, I would yuse a vag...but I don't have one yet. Please help me if you can because I need to try and get this fixed as soon as possible.

Note: I would have done a search but I am at my inlaws house and they still have 56K!! So, it would take about 3 hours just to do one search.

Thanks!

 

Check ignition coil module. Here is a DIY site to check that. Also,here is atroubleshooting guide.

http://www.audidiy.com/b5a4.html

https://www.audiforums.com/m_311488/tm.htm

 

The ignition control module sits on top of the airbox. It is very easy toput in a new one.

I f you swap a coil from a working cylinder with that one, and the misfire stays in the same cylinder, it either the ICM (likely) or a problem with an injector (not as likely). If its an injector problem, the plug will be dry, no gas on it. If its misfiring, and you pull the plug, and its wet with gas, its just not firing.

You didn't say which cylinder was misfiring, but I would put my money on number 2.

 

Wow...thanks guys. I'm gonna go out right now and check these things. And if the second one back from the front is #2...then you are correct! I'll let you know what today yeilds.

Edit: I tried to find the DIY for checking the ignition control module on the DIY site but had no luck. I must be blind but could you give me a link right to the page? Thanks!

 

If its number 2 (second back from the front)I can assure you all you need to do is repalce the ICM.

I bought the HUCO brand one for my car,itcost around 150 or so.

 

It worked!! Put a new ICM in and it fired right up no problem. Now my check engine light is on and I need to turn it off. I don't have a VAG yet to do this....any suggestions??

 

It may go off on its own in a couple of hundred miles. Otherwise autozone will pull codes for free and turn it off. You can also try to find someone with a vagcom using the vagcom locator link in the helpful links section.