In my frustration, I neglected to mention a few points that fellow listers
have mentioned.
1- Idle speed controller tests, appears to be clean, and moves freely.
2- Throttle position switch connector is clean, tight, and shows no sign of
corrosion
3- Code checks have been inconclusive because of the intermittent nature of
the problem. Two local dealers and one independent have found no problem and
have not been able to duplicate the problem. All have cleaned the ISC and/or
replaced the TPS.
4- Computer failure may be a possibility but to date have not had a hard
failure that has been traceable.
5- I had not considered a marginal temperature sensor and the impact to idle
operation.
6- Typical problem occurs when the engine has only been operated under light
load for less than five minutes of operation, engine is shut down for a short
period of time, and then restarted. (Wife dropping kid off at child care in
the morning or running short errand.) Time of day or external temperature
does not seem to be a factor.
7- The Jeep will run fine for approximately 12 months after the switch is
replaced and then start acting up. Not quite like clockwork but we have
experienced 6 failure in seven years of operation.
8- After the engine has reached operating temperature, operation is mixed.
Sometimes it works like a champ, other times I wished I owned something else.
No clear pattern has developed.
9- I am not a fan of replacing parts without a clear understanding of the
why. Unfortunately, I have not been able to determine the problem. My
professional service technicians have been unable to determine the root cause
as well.
10- Local parts houses here in L.A. say the TPS is a dealer only item. I
would love to hear that the aftermarket has a solution. Any suggestions?
I very much appreciate the comments of all that replied. Thanks Mike, Ben,
and Roger. Randall, I will pursue a copy the NHTSA service bulletin, thanks
for the reference.
Regards, Kevin
P.S. I am not slamming Jeep products, I own many of them, love them dearly.
I just wish I could resolve the persistent idle problem with the GC.
|