High RPM at cold start-up...anyone else?

[97puddlejumper]

1996 5spd awd. Upon cold start, engine will buzz to ~2200-2500RPM, even when its 80 degrees. As engine warms-up, RPM slowly decreases and becomes "normal". I have disconnected throttle cable and started it...no change. I have replaced coolant temp sensor....no change. I have looked for a bad vacuum hose....nothing found. Anyone with this experience? Thank you in advance for any help. Craig

[03rav4inPA]

It's common to experience this with 4.2 and 4.3 rav's...I don't see why this would be an issue with a 4.1. Sounds mostly normal to me. If it didn't come down to normal rpms I'd say something was wrong. Mine takes a couple mins to come down, but I also let mine run 5-7 minutes when it's cold out just to be safe.

[97puddlejumper]

It's not normal. This recently started. It should cold start around 1800RPM. BTW-releasing the clutch will reduce the RPM while still cold, but it's still to fast. According to the shop manual, IAC valve problems are associated with warm engine idle but no specifics are provided for initial cold start situations.

[Ken Allistone]

Could be the EGR valve, can't explain how it will be open and then closed when warmed up but it's easy to check, if it were constantly bleeding air the engine would hesitate though.
Blank the vac pipes to the modulator just in case that's faulty and check the pipe from the modulator to the EGR valve too.
Is the PCV valve and pipe to the inlet manifold ok?
Sounds like an air leak, you'll need to isolate as many of the connections to the manifold as you can, brake booster, the 'other' vac pipe adjacent to the MAP sensor pipe (runs real bad without a MAP connected), not sure if you have a vac pipe from 'E' port on TB to charcoal canister, it goes via a valve that opens when engine warmed up. Throttle position sensor maybe?
last resort remove and clean the IAC, good luck.

[97puddlejumper]

Thanks a lot Ken! I will continue my search. Craig

[mensajero]

It's normal dude. Until the sensors can detect normal functional temp. It will shoot a ton of fuel until it levels out to get the engine to normal operating temp. This is very normal in cold to very cold weather. In PR, this only happens in the morning (if you can call 65 to 70 degrees cold in the AM at most) In the USA, if you are in the very cold states, Minnesota, Maine, Chicago, etc. this is common.

[hungry_squirrel]

My RAV gets up there when I start it in the morning sometimes too. I figured it was pretty normal.

[mensajero]

Originally Posted by hungry_squirrel

My RAV gets up there when I start it in the morning sometimes too. I figured it was pretty normal.

It is.