1992 Toyota Corolla

Engine Performance problem
1992 Toyota Corolla 4 cyl Front Wheel Drive Manual

hi can you tell me the role of sensor assy vacuum in obd 1 vehicle. My car idle is high. Where can it have vacuum leak? Or any solution to lower the idle.
September 28, 2009.

Check all the vacuum lines for cracks.

Look at the injector seals, make sure they are seated properly.

Check the intake manifold gasket.

Car is equipped with an idle air control valve, it is mechanical, located under the throttle body. I have to say that these rarely go bad.

There is an idle adjustment screw but, DO NOT ADJUST it until you find the vacuum leak.

I just had the same problem on a 91 Corolla, turned out to be the intake manifold gasket.

Sep 29, 2009.