i have a 96 jimmy with a 4.3 v6. lately, when i start it up and its cold outside, the vehicle will not start, but when it finally does, it idles very high, between 2500-3500rpms and will not go down unless i turn the car on and off about 3 times, then it idles fine at 1100rpms. its like the motor is overcompensating or working too hard to keep from stalling out.can anybody give me any sort of advice, i really need help. i also just replaced the fuel filter and sending unit. thanks
need help, extremely high idle
- Thread starter cb96
- Start date
Molson02536
New member
Start with the simple and clean your throttle body. Make sure you use throttle body cleaner, Carb cleaner is to corrosive for the gaskets used on the throttle body's.
Make sure you get the IAC (Idle Air Control) valve cleaned. On the back side of the throttle body, you'll see the IAC passage way. Just follow the instruction on the cleaner, If its really dirty. you going to have lots of smoke coming from the tail pipe for up to 10 min. No worries, the smoke is just carbon and the cleaner burning off in the engine.
If this does not fix it, then you most likely have a bad IAC valve and will need to be replaced. Cleaning the IAC will fix the issues your having 95% of the time.
Good luck and be safe, post back and le us know if this addressed your high idle and we can go from here to getting your Jimmy running 100% again soon.
Molson02536
syclonetycoon
New member
bet if your IAC does not fix it your throttle body gasket is bad along with you having an intake leak. had the prob on my astro last year gaskets were shot cheap to fix but try the IAC first.
also check you coolant levels, in my 94 i had a bad heater core and lost 90% of coolant and it wouldn't start when cold and when finally did it idled really high until you revved it up some more and got it up to temperature
syclonetycoon
New member
spray throttle body cleaner around your intake and throttle body housing and check for leaks if the engine starts to bog you have an intake leak if the iac does not solve the problem they usually stick and die with the iac either all the way out or in. they arent that bad to replace just make sure to snug it in properly. learn the pin out to extend and retract the iac to make sure its functional before you replace it rule of thumb with polarity, take the old one out and run voltage to the 4 pin connector it should extend and retract. just remember which is pos and neg.