When I'm driving along and I push the clutch in while I'm still rolling my idle stays at 2000 rpm until I come to a complete stop then it falls back to 1000 rpm. I causes this?

 

The PCM opens the idle air control valve when the vehicle is moving and the throttle is open, to prevent stalling on sudden throttle closure. The RPM at which the engine is held under these conditions is also programmed higher than the closed throttle/zero velocity condition. Since you have obviously had the PCM reprogrammed for a heads/cam 383, you might want to ask the programmer if he elevated the RPM for closed throttle when the vehicle is moving. You also might want to data log the PCM to observe the IAC counts under various operating conditions to confirm this. The PCM should also cut fuel under certain "coast-down" conditions. Maybe the fuel cut off has been modified in the program.

 

Interesting the car has a mail order tune. I am going to get it dyno tuned soon and have them check it out. Thanks

 

My car idles at 1500 when moving. 2000 seems kinda high but maybe thats what it was programmed for. It helps with vacuum

 

Well today I'm getting a ses light. I pulled the code and it's coming up 0507 which is idle control system rpm high. What are your guys opinion on that?

 

Sounds like the IAC valve may be sluggish or not responding correctly to the PCM step commands. Put a scanner on it and observed how the PCM responds to high idle. Is it now also idling above spec when the car is standing still?

Have you checked the throttle linkage to insure its not sticking?

 

The idle still is doing the same thing when rolling it idles high but when I come to a stop it falls down to were it should be. Could the problem be I have the set screw turned out little bit I had to open the tb blades a little bit to keep the car from dying

 

P0507 will set at idle (passive test) or with the vehicle moving (intrusive test). That would indicate the true idle speed may not be returning to the programmed value when the car is standing still. (Passive test - TPP <1%. VSS <1MPH, condition lasts more than 8 seconds; Intrusive test - Idle low for more than 5 seconds, MAF between 10-35gps, VSS between 20-77MPH, TP change less than 2%, IAC position greater than 52 steps, IAC ramped in upped to 45 steps).

Opening up the throttle blade with the set screw can mess up the TPS colsed throttle voltage, which will also cause a high idle (although if the voltage is high enough to do that, it should also set a code, and when there is a code for TPS, it won't set a code for idle RPM).

First, you need to verify the tune. If you are having to increase idle air because of the tune, it may need a rework. Or you may have the classic idle air problems related to aftermarket throttle body (is yours stock or aftermarket?). Then you need to verify the TPS voltage and check the IAC counts at idle. Then you need to watch the IAC counts as the engine runs through a range of operating conditions.

 

I got a bbk 58mm tb.I got the tps sensor adjusted properly but I can't check the iac counts I don't have the proper tools to do that. I'm going to get my car dyno tuned I'm going to have them straighten everything out.