98 Chevy S-10, erradic high idol

MJE_IGGY

MEMBER
1998 CHEVROLET TRUCK

1998 Chevy S-10 2WD, STD Transmission, 96000 miles. I had been having problems with my AC. When running the AC and after having pressing the clutch the RPM's would jump to 3-4000. When attempting to drive after that point the truck would stall. I remedied this by simply not using the AC and leaving the dial on heat. But now I am experiencing slight raises in idling when the clutch is pressed. It will raise to just over 1000 and remain that way for a few seconds and then return to normal. I have just recently had the Service Engine light come on and I have a TPS reading. 2 questions: 1) what is wrong with the AC and 2) could this new reading stem from that problem?

1 Reply

MIKEYBDMAN

MECHANIC
623 POSTS

First off, the Throttle Position Sensor can cause your problem. The Vehicle Control Module calculates fuel delivery based on throttle valve angle. A broken or loose TP Sensor may cause intermittent bursts of fuel from an injector. This may cause unstable ide because the VCM detects the throttle is moving.
Another place to look is the Idle Air Control valve located on the throttle body. This unit control the engine idle speed during changes in engine load.
Hope this helps.