My car has the LT4 conversion with the PCM reworked by Ed Wright. Now after three years it will not idle right. It idles low so I turn the idle adjuster in and it idles too fast, turn it back to stock idle then it starts surging again. Is the TPS going out or is it something else?

Thanks,,

 

might try taking the tb off and cleaning the idle air control valve real good and make sure it is functioning.

 

I second cleaning the IAC and passage way. Be careful cleaning it as it's delicate.

You might also check for vacuum leaks.

 

Thanks, This is where I will start instead of just start changing parts.

Thanks again,