alexflan

In May of this year I purchased a 2009 Audi A3 s-line with ~155,000Km on it.

About a week after the purchase, the CEL came on reporting cylinder 1 misfire. I started by replacing the coil followed by the spark plug with no change.

The problem has been getting worse from that point on with more frequent misfires and running rough.

By running rough, I mean that the car kind of shakes when accelerating. It feels like it's jerking to take off and then loosing power.

Now here's the odd part... this only occurs when the car is below its 90 degree running temperature. Literally this will occur right up to 89 degrees and the second it hits 90 it'll drive like a completely different car.
Additionally, it only occurs when running between about ~1500-2500 RPM. If I drive it down a gear or two it's fine but horrible for my fuel economy. A few times, I've continued to accelerate through the jerking and the ESP light will come on. After that, the car runs very rough until turning it off and back on again.

It's at the point where I cannot turn the car on and leave it idle without the CEL blinking reporting misfires... and only in cylinder 1.


The next step appears to be to open things up to replace the injector and possibly a carbon cleaning but I would prefer not to pay for that if I don't have to.

Any thoughts on the matter would be great and much appreciated.

4taz

Disconnect the MAF sensor and drive it for a while, see if the car drives better. if it does, clean the sensor or replace it.

Note: you'll have a xmas tree like lights in the dash (check engine, ABS, ASR). Ingore them.

Are you chipped?. Keep us posted

alexflan

No, everything is stock.

Thanks.

caferacer

I know this is an older post but was wondering what you did to resolve the issue. I have a 2011 A3 2.0TFSI manual shift with the exact same issue. Mine is manageable to drive but really annoying until it warms up. It stops exactly at 90 degrees. I have been trying to figure this out for the past 6 months with not good results. My first step is to replace the ECT (if I can find it's location, that's another thread...). Any insight would be much appreciated. Cheers!

Donald Kaufman

Fuel injectors and decarb

caferacer

Thank you. I ended up having both done and the result was great. No more hesitation and/or lurching. Fuel economy has improved dramatically. Went from 420KM / 55l to 520 / 55l. What an improvement. Thanks for responding on an older thread. Cheers from Vancouver Canada!