'90 LX 5.0L 5-Sp Unintentional Revving

[LEM]

While driving into work this morning, my car started revving up to about 2,000 RPM when I stepped on the clutch. Every time I shifted gears, the engine wouldrev up to about 2,000. I seem to remember someone suggesting that the Idle Air Control valve might need to be cleaned. Any ideas?

Thanks.

[Blue)(Fusion]

Check for a vacuum leak first. Listen for a hissing noise along the vacuum lines. You can get a vacuum gauge also to check for proper vacuum pressure.

If no vacuum issues are found, than clean or replace the IAC valve. They've been known to go bad.

[HiFlow5 0]

Originally Posted by Blue)(Fusion

Check for a vacuum leak first. Listen for a hissing noise along the vacuum lines. You can get a vacuum gauge also to check for proper vacuum pressure.

If no vacuum issues are found, than clean or replace the IAC valve. They've been known to go bad.

These are all great steps to try. Also these cars also had a recall many years ago for the 10 pin harness needing a jumper wire installed by the dealer, to fix an issue similar to what you described. Do you have a dealer certified sticker stating that a 10 pin jumper wire assembly was installed? If you are driving when this happens, are you able to turn the car off and restart it without the issue happening again right away?

Technical Service Bulletin; 91E19 MAR 92 Recall - Wiring Harness Modification

[LEM]

Originally Posted by HiFlow5 0

These are all great steps to try. Also these cars also had a recall many years ago for the 10 pin harness needing a jumper wire installed by the dealer, to fix an issue similar to what you described. Do you have a dealer certified sticker stating that a 10 pin jumper wire assembly was installed? If you are driving when this happens, are you able to turn the car off and restart it without the issue happening again right away?

Technical Service Bulletin; 91E19 MAR 92 Recall - Wiring Harness Modification

I’m resurrecting an older post. I'm having idle problems again. I replaced the IAC and it still is giving me problems. It's intermittent and I cannot see a pattern. This morning I drove it to work with no issues; drove home at about 9:30 AM and it started revving up again. I turned off the engine and restarted it and it seemed to calm down. On my way back to work at about 10:45 AM, it ran fine.
I have not heard any noise that might indicate a leaking vacuum hose. Where all do I need to listen for one? What else can I check?
Thanks.