I have searched this site for info on setting these and printed them out. My car will start and die when I don't keep my foot on the gas and keep the RPM's up. Once the car warms up it usually runs but when I turn off and start again it will die again.

I took off the air assembly so I could have a look into the plenum and get to the IAC and try to unscrew it. I opened up the throttle and put my fingers into the plenum. I pulled my finger out and it was full of black grease and smelled like unburnt fuel. The passages should be clean right? All the walls inside the plenum are so greasy that it is not funny.

Okay I just got back after trying to set the idle speed and the lowest I could get it was to 550-600. The screw came out further but had no affect on the Idle as the Throttle just sitted at the spot on its own. Before I did do that all I did was unplug the IAC connector and wipe it over with my hands. I put it back together and the car seemed fine. I tried unscrewing the IAC but could not get to it properly and I could not loosen it with my fingers.

I know the car is still running rich as my scanner jumps from Lean to Rich every second.

Anyone have any idead why the throttle body is so greasy??

86 IROC
T700
Converted to MAP
305 TPI

 

When you shut the engine off fuel that has been injected into the manifold drifts down onto the intake valves and vaporizes. Those vapors waft up the runners and condense on the tb, plenum, and runners. Long term accumulations have been known to cause many problems like, stumbles, hesitations, hardstarts, etc. I think you have a combination of problems. First clean out as much of the throttle body as possible with a toothbrush and throttle body cleaner (not carb cleaner). Or better yet find a place that has a motorvac and have that hooked up. They work, I know from experience. Secondly set the minimum air rate. Remember put in field service mode, chill for 2 minutes and start the engine after disconnecting the iac. Set the rpms to spec for your car. Make sure to use the factory spec!!!! Next set the tps to specs. I believe that will solve your problem. If things are significantly improved but not 100% perfect disconnect the battery and follow the idle relearn procedure. That sure clear up any remaining roughness. The scanner jumps from rich to lean because it is reflecting the switching of the o2 sensor. That is perfectly normal. A consistant rich or lean indicates a problem. Lastly, I believe you were setting the idle right but the ecm was not in field service mode(iac not fully extended). Also try spray tb cleaner down the iac passage in the tb.