Has anyone figured out the high idle when shifting Its driving me crasy.I replaced the iac and I thought it was gonna stop my 3000 idle when shifting if I am sitting still the idle drops down like normal just does this while moving during shifts. I have checked cable spring, cleaned throttle body,replaced iac checked pvc, checked for vacumn leaks and it still happens.

 

What...?

Explain further.

 

Manual trans.
The computer will maintain RPMs when shifting if speed is above 5MPH, this should last only a few seconds, maybe 5 seconds at most, this is an emissions requirement.
RPMs should then drop to 1,000-1,200, and then to normal idle level, 700-750(warmed up), below 5MPH.

Unless you where at 3,000RPMs when shifting it shouldn't go up to 3,000, that would most likely be a computer error.

Speedometer working OK?

Computer also has REV Limiter if speed is below 5MPH, rev limit is about 3,000rpm

If you have a OHM meter or volt meter I would check the TPS(throttle position sensor) it is a long shot but not a no shot, lol.

 

Did this do this before you changed the IAC?

 

My 2003 has the same problem.
I kick it down but have changed nothing.

PITA at times but living with it.

Looking for a reason to do a 5.0 swap.

 

[QUOTE=RonD;2077799]Manual trans.
The computer will maintain RPMs when shifting if speed is above 5MPH, this should last only a few seconds, maybe 5 seconds at most, this is an emissions requirement.
RPMs should then drop to 1,000-1,200, and then to normal idle level, 700-750(warmed up), below 5MPH.

Unless you where at 3,000RPMs when shifting it shouldn't go up to 3,000, that would most likely be a computer error.

Speedometer working OK?

Computer also has REV Limiter if speed is below 5MPH, rev limit is about 3,000rpm

If you have a OHM meter or volt meter I would check the TPS(throttle position sensor) it is a long shot but not a no shot, lol.It

 

Yes it did this before the new iac. only thing that is wrong is I think themostat is fryed as the temp gauge barely goes up when warm. maybe that's the cause will get a new themostat on payday.But ya I literly have to put it in fifth gear when coming to stop to slow idle down. or else it will stay at 2800 to 3000 till I drop below 5 mph. I have read threads that some had their pcm reflashed for this problem but it worked fine for almost 12 years,so I don't think the pcm forgot how to to set idle.Any ideas ,will try anything to get this to go away.

 

Well that's kinda the way PCMs have a problem, they work fine until they don't.

I assume you have unhooked the battery for longer than 5 minutes while working on engine.
That can reset PCM, and see if the high RPM continues or comes only after driving a bit.

If you can get a Live scanner you may be able to find a fault in a sensor reading, faulty wire or sensor.

I think the '02s had the PCM connector moved to upper near center of firewall, it would get water inside there, they added a cover to it in later years.
So you could just have a little corrosion starting in that connector

 

I checked out that connector and it was fine as it had a cover.Usually it will shift fine during the first maybe 5 or so miles, just noticed.

 

Thinking on this my ideal goes high only when going slow, crawling, less than 10 mph.

 

high idle is usually a idle air controller, tps or pcv problem.

since you've changed your iac and pcv already and cleaned your throttle body you may want to have you tps check to make sure that the closed position voltages are within expected range.

 

Well all after I put a new thermostat in and left battery unhooked all nite everything is back to normal whoo hooo No more high idle shifting.

 

My '94 does this too. I'm stymied.

 

Hey, how's this working out ?

Still working ok ?