90 lumina idle speed

what rpm should this car be ideling at? Mine seems to idle at 500-600 rpm. Seems too low to me. There is an adjustment bolt in the throttle body which would appear to hold the flap open some more. I suspect this thing should idle around 900.

Is that idle speed in gear with you foot on the brake, or in park? If in park , it's too low (should be 750'ish, 900 is too high). In gear, 600 is about right.

That screw on the throttle linkage, is for adjusting the minimum idle air and usually sealed. I wouldn't fool with that unless your having a problem.

There might be an emissions sticker under the hood that may list the specs.

This is just some generic specs. v6--750-850, 4--750-1000. I didn't see an engine size listed.

Sometimes, just cleaning the throttle-body and idle air passages will help.

Yea thats in gear & foot on the brake.
I seem to be having other problems. Car runs rich & might be missing. Not sure what i'm going to do next.
I've noticed that the vac line going to the carbon filter never seems to build any preasure or resistance. There seems to be a solenoid in the line. Is it supposed to open and close? I've blown air through this line without resistance with the car running and when its not running. Is this normal?