black smoke, stalling, racing idle.

[rodwa4]

my 94 talon dl spits black smoke out the back when i accelerate. when i push the clutch in, the rpms drop to about 400-500, and the car even dies at times. the idle speed is all over the place, somtimes around 500, and other times around 2000. i replaced the o2 sensor, but that did nothing. any suggestions? thanks, dwight

 

[90CherryTSI]

I have a 90 TSI and once it warms up while I'm driving if I push in the clutch and coast to a light or something it'll drop to 500 then catch itself and go back up to 1000. It had died more than once because it drops to fast and doesn't catch but I can pop the clutch and it comes right back. I have a steady 1k idle most of the time if I'm sitting. Someone at work said it may be related to some sensor causing my RPM's to cycle during warm up from 1 min at 1k, drops to 500 for 15-20 seconds, then up to 2k for a couple seconds, then settles at 1k THEN it's driveable. Any sensor that may cause a problem like this or the one dipping the RPM's when the clutch isn't engaged? If I'm slowing down almost to a stop using the engine to brake partially it won't drop, it just settles. What about some big time vac leak? Or a boost leak? My vac is steady at -18 when idle...thanks guys

 

[R3dR]

sounds ike a failing IAC motor

it doesnt go goofy untill the car is stopped or unless you hold in clutch because the transmission is making the engine pull.

When it gets really bad it will even surge when your coastin in parking lot.

You need to go into the gambit of eliminating items that can cause the same situation.

loose vac line
boostle leak
dirty throttle body
ect.

 

[rodwa4]

ok i feel real dumb but, i purchased a new IAC motor, but when i went to put it in, the old one was just unplugged. i plugged it in and... the car runs great. oh well.

 

[90CherryTSI]

my problem was a faulty o2 sensor. After replacing, runs great now! Good news!!!