1992 Toyota Camry engine reeving high when started

ROB LITTLE

MEMBER
1992 TOYOTA CAMRY
3.0L
6 CYL
2WD
AUTOMATIC
157,000 MILES

1992 Toyota camery when I start it the rpm will go up to 2200 then right back down to 750-1000 rpm. The first thing I did was cleaned the idle control valve out and put it back in place. 2nd one was throtle body and the butterfly I cleaned out used starting fluid I think that was the wrong fluid but after I used carb cleaner both of them were real carb up. 3rd I also looked at the hoses for a vacuum leak didn't find one also put a new pvc valve on it. Do you think it could be a pcm unit? Cause there is a few things it does say it could be that cause when you shift it from park to drive the rpms goes up some. Then the cooling fan goes real slow also plus I think it shifts funny but im not sure thou. Where is the pcm unit located at? Maybe the spark plugs are dirty? That's why its idleing rough? Thank you for your time.

1 Reply

CARADIODOC

MECHANIC
33,871 POSTS

Unless I'm missing something, what you described is called "idle flare-up" and it is what all fuel injected engines are supposed to do at start-up. 2200 rpm seems a little high, but the fact it comes back down right away proves there's no vacuum leak, and it proves the idle air control valve is working. It will increase engine speed slightly when you shift into gear or turn on the air conditioning to make up for the added load on the engine.

You made a comment about idling rough but didn't elaborate on that. You don't suppose a misfire would affect idle speed, do you? The Engine Computer has enough control with the idle air control valve to overcome a misfiring cylinder, but that changes the characteristics of how that system will control idle speed and respond to needed adjustments as the engine is running.