ok. here is my issue. my blazer is idling at 3k RPMs. 97 4.3l 4 door 4x4. The SES light came on last week for a TPS sensor. Swapped out the TPS sensor did nothing. Have since replaced the following : Cap, Rotor, Plugs, Wires, Coil (AC Delco) Removed IAC and cleaned carbon deposits, checked fuel pressure (within specs), replace fuel filter, no vacuum leaks found. Nothing seems to change anything. Any help? I have access to a fairly high end scanner and can watch live data, but i dont know what to look for. the SES stays off now and has no current/history codes stored. i am at a loss.

 

so i talked my electronics company into looking at the truck. updated the PCM, tried idle relearn, tried to adjust idle manually, nothing was working.. power going to the IAC but not moving to compensate. Have a new IAC on the way.. hope it works!

 

What was the DTC? When the DTC set, did the flow chart specifically tell you to replace the sensor, or did you just replace it?

With the engine off, do the cruise and throttle cables both have slack at the throttle body?

The throttle stop screw on the throttle body is adjusted during assembly. There are no procedures in the GM shop manual for adjusting it. Once the high idle problem is fixed, there are ways to get it close, but it requires a bidirectional scan tool.

 

the new valve fixed it. i am glad to have it running right again. i dont remember what the DTC was, but the flow chart did have to replace the sensor, and he also pulled it up on identafix and that is what was recommended having solved that issue before.