Can anyone help me pls, my Audi A6 1.8T Automatic 1997 is running roughly. I run completely out of fuel one day, manage to get fuel by an emergency container and fill up car. Next day engine started to vibrate, became noisy and hesitates on turning. I have replaced fuel filter and tried replacing fuel rails and the whole set of injectors. I suspected that injector #4 (the one which is at the far back of the engine) as condition of engine stays the same as i disconnect wire while engine is running, unlike#1,2,3 which makes engine run rougher when I disconnects them. When I first change all injectors and fuel rail, fuel started to leak from injector #4, so i thought it was a bad injector and replaced it and the leaked stopped. Engine still vibrates, noisy and still hesitates and no change when I disconnect injector # 4. Pull spark plug out and it smells gas so tried to replace, still the same. Pull plug again to check and still smell gas. Exchange coils and nothing happens and now I don't know what to do.......any other parts I could check....

 

Do you have any missfire faults or are you just guessing?
Im guessing this is a euro spec vehicle as well because we don't have 1.8T's on A6's in the states.

 

Well since you don't wanna respond i'll give youa hint, if you have any miss-fire faults then you need to replace the power output stage, or ICM (ignition control module)as the kids in the A4 section call it.
It sits directly on top of the air box and has an electrical connector on both sides of it.

 

thanx auditech79, I'm pretty sure that its a misfire because the engine's rpm stays the same when I pull out injector's plug. its a Euro spec alright and I might be wrong that the ICM might be the Hall Sender as they call it over here. Also I have been driving the car like this for a while, will it take a while maybe for it to run smoothly while ECU identify working injector or maybe have to disconnect battery to reset ECU. Do you think this would help?

 

Stop touching the injectors, they never fail. You need to check the fault codes, if you check engine light is flashing then you need that ICM im talking about, and no its not a hall sender. A hall sender would be your cam sensor which isn't your problem most likely.
Secondly STOP DRIVING THE CAR IF IT HAS A MISS FIRE! Your going to damage the cat converters that way.

 

I took ICM (4D0905351)out as a ref and look for replacement but no luck and kept ICM at home overnight. Next day I put back ICM to car and tried to start the car but won't start. Took it out again to search for replacement and this time I was lucky. Installed new ICM (4D0905351) onto the car and tried to start car but still won't start. Tried it many time but no luck. Checked all spark plugs and they were soaked with gas. Is there anything else need checking?