1995 gmc sierra 1500
I get high idle after shutting it off after it’s been running for while. 255,000 miles, changed the Iac and cleaned the throttle still does it. Also when it’s high idle and you put it in gear it jerks, only does it when idle is high but when idles normal it’s normal. Could it be tranny or throttle itself.
Of course it's going to jerk if put into gear at high idle.
Check to see that the IAC valve is operating properly and that there aren't any leaks letting unmetered air into the intake. After nearly 30 years there's bound to be degradation in hoses and wiring.
Just installed a new Iac today and wires and hoses are good
Just installed a new Iac today and wires and hoses are good
Was it OEM or aftermarket? Did you test that the IAC is being triggered by the ECU and that it is actually operating properly? High idle would normally be engaged when the engine is cold, have you tested that temperature sensors are working properly? Is your throttle assembly or cable sticking?
1995 gmc sierra 1500
I get high idle after shutting it off after it’s been running for while. 255,000 miles, changed the Iac and cleaned the throttle still does it. Also when it’s high idle and you put it in gear it jerks, only does it when idle is high but when idles normal it’s normal. Could it be tranny or throttle itself.
If you have an OBD2 capable vehicle, look at what the IAC reads via live data. It should be within a gram or so per liter of displacement at idle. Your vehicle may not be OBD II capable, it was standardized in 1996.
