ok, so i got my 89 s5, n/a, engine rebuilt recently, few days ago, fired it up, mechanic said that it was shooting out black smoke and it doesn't idle unless given gas...

so, with all the problems and faq's, just to clarify,
black smoke means fuel problem, so bad fuel lines/filter/pump/injectors right??

and the not idling unless given gas means a bad TPS sensor?

then i would have to replace my fuel lines/filter/pump/injectors and get a new TPS sensor to keep the car smooth right?

any other suggestions appreciated, been in the shop for almost 1month already >_>

 

Black smoke means it is running pig rich obviously. I would suspect the injectors above anything else you mention. Were they changed out when the engine was rebuilt? Maybe the wrong size injectors were installed. Or maybe one of them is faulty allowing a constant stream of fuel flowing into the intake.

Also, make sure the AFM is plugged in, all hoses are attached to the intake pipe and all clamps on the pipe are secure. Once you get the engine warmed up, adjust the TPS.

 

mmm i see, i'll be sure to follow up when i see the car again monday, could it also be a bad ecu?