1997 Chrysler Concorde Idles Weird

1997 CHRYSLER CONCORDE

89,000 MILES • 6 CYL • FWD • AUTOMATIC

ADAMR32

MEMBER
1 POST
FOLLOW

I took my car in recently because the car was wobbling a bit, and consequently, the check engine light lit up. The car was given a tune up, and I was told that the tune up fixed the problem. It did not! I went back again, same mechanic, and was told I needed a new fuel injector for the fifth cylinder. Got that done, same mechanic. He said that it was fixed and runs like a dream, but now the idle is funny.
After starting it up, it idles about 900 r.p.m.'s, then a few seconds later jumps to 1400 r.p.m.'s. This goes round and round. Can you give me your expert opinion on this matter?
Thanks,
Adam

Mar 24, 2009 at 12:42 PM

CARADIODOC

CAR REPAIR CONTRIBUTOR
34,309 POSTS

First of all, get it up to speed on the highway, then coast for at least seven seconds without touching the brake or gas pedal. This will trigger the engine computer to relearn minimum throttle. If that is lost from memory, the computer won't know when to control idle speed and when you have your foot on the pedal.

With a new fuel injector, fuel metering is different than before. It takes a while of driving for the computer to relearn "short term fuel trims" before it can adjust fuel mixture for proper operation. The same thing can happen when the battery is disconnected or run dead.

If these things don't work, take the car back when the mechanic can have it long enough to reproduce the same driving conditions as when the problem occurs.

caradiodoc

Mar 29, 2009 at 5:50 AM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.