'89 2.8l

[markaz]

When my '89 gets to normal running temp the idle RPM goes from smooth to literally bottoming out then to smooth and the cycle, about every 10 seconds, continues. I read the previous asked question and wonder if this qualifies as the same type of problem.

http://www.automotiveforums.com/vbul...d.php?t=104536

I did have to replace the battery but don't have any idea if the idle problem started just after battery rplacement. Checked the EGR and it works properly. Plugs changed. Any help would be appreciated.

[Kooterskkar]

Sounds like you may have a vacuum leak. Check all the lines and hoses for cracks and breaks. Also replace any hoses that are dryrotted or brittle.

[markaz]

They all seem fine to me BUT it's a 147,000 mile buggy with the original hoses. Probably should replace anyway! If it was a vacuum problem would it be problematic even when its running cooler?

[Kooterskkar]

You might want to replace your CTS too. The one near the thermostat.

[markaz]

Vacuum leaks and the CTS........are these common problems for an older Corsica? My wifes got a '91 Corsica and it exhibits the same symptoms.

[jefro40]

my 92 does this when ever you disconnect the battery, i think it has something to do with the computer having to be re-taught. it should clear up by itself,if this is the same problem that i have.may take a few days of driving for it to be re-taught.

[Bupahs]

I have an 89 2.8MPFI.. I had the same problem, took a while to figure itout butonce I did.. problem has not returned. This was the fix for me. The EGR did not have a gasket.. at some point in time the EGR was replaced and either the installer did not feel the gasket was needed, or simply did not know it was needed. Anyway, vibration, heat you name it caused the EGR to come slightly loose creating a vac leak. I put on a new gasket and problem went away.

NOTE, I have noticed that many are not sure what the idle reset for the Corsica is. When replacing anything connected with the idle (Idle air valve, Throttle sensor, EGR etc) one has to teach the computer... the fast way is to make the repairs, turn the car on and let it idle until the rad fan comes on, turn off the car, wait 5 minutes turn car on and let idle until fan comes on again, turn off the car, restart and drive the car for a few minutes at or above 40 miles per hour. This resets the computer and the idle.

I have an 89 Corsica Lt with 214,912.8 miles on it. Runs perfectly (no major overhauls or repairs). I have owned this car since 1998. The interior is spotless, paint job excellent and it is 90% factory original. Yeah I baby this car.