Whenever I am driving my car and its warmed up, and coming up to a stop - If I put the clutch in and/or shift to neutral (and let clutch out), coasting up to the light - My RPMS will not drop below 1500 until the car makes a COMPLETE stop . The instant the car stops rolling, the rpms drop to 900ish, standard idle. - doesnt matter if its in neutral and clutch out or clutch in and in gear, always the same result when coasting up to a light, always repeatable - regardless of whether driving hard before hand or just cruising.

Any Ideas?

 

No guesses?

 

The Idle air control valve (IAC) adjusts the idle speed and is actively controlled by the ECU. System monitors multiple input parameters and determines what to do. Commonly we think in terms of actual RPM, electrical loads, A/C, etc., but your findings suggest there may be feedback on vehicle speed, too.

Did you test starting to coast from wildly different speeds, too? This might change the 'time' needed to drop the RPM rather than just absolutely stopping the car.

 

Yeah mine kinda does the same thing. Thought it was normal, possibly some emissions things. Since I've had other cars like a 2000 chevy s10 did somethin similar.

 

Since first reading this post I've paid attention to my own car's idle behavior. Just like BicuspiD says, the idle speed doesn't totally drop until my car comes to a complete stop. Mines a '95 PEP and the effect is most noticeable when the A/C is running, but it’s doing it either way.

 

Same here, I remember reading about it but cant remember where. I think it is toatlly normal, just need to find the site to back it up.

 

I tested it today and it will actually pull my car up to 1500rpms, accelerating me when I am in higher gears (coasting at ~20 put it in 4th)

If I just crawl forward, like in traffic and dont get the car above ~10 mph it doesnt do it at all.. perhaps the car has to reach a certain speed before this " enrichment" is activated..

Faulty clutch switch maybe?

 

I suspect a vacuum leak, as mine does this also but it didn't in the past. It started after some particularly hard driving a few months ago.

My hope is that a planned hose job will resolve the issue. I'll post results.