1991 Chevy Corsica Engine idle

JIMOXFORD

MEMBER
1991 CHEVROLET CORSICA

Engine Performance problem
1991 Chevy Corsica 4 cyl Two Wheel Drive Automatic

Car idles rough and somtimes stalls when I stop. I, ve changed: plugs, plug wires, idle air control valve, fuel injector, fuel filter, PCV valve, intake manifold gasket, TBI to intake manifold gasket and crank position sensor. I, ve checked: timing chain, throttle position sensor, vacuum hoses (found no vacuum leaks) (vacuum is unsteady do to poor idle), fuel pressure (11.5 psi), and cylinder compression (around 125 psi). All good. No error codes.

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Check the EGR and PCV valve-also test the fuel pressure -check for vacuum leak-

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Monday, June 30th, 2008 AT 9:36 PM

CHARLIE LEGERE

MEMBER
1 POST

I own this same vehicle but mine has a 3.1 V6 engine. What I have learned about this car is that the idle is not "automatically" set by the ECM. The manual states that if you disconnect the battery the car must be taken to the dealer or a repair shop to have the Idle reset with a T1 diagnostic tool so the system can "re-learn" the proper idle setting. If any of the electronic sensors are not working properly it will send incorrect signals to the ECM and the car will not idle properly. This is a problem I have battled with constantly with this car since I've owned it. I've just learned to live with it and at 189K miles and still going I don't worry about it any more.