I have defeated my the stuck (unstable) idle monster
Idle would stick at around the 1500 RPM with engine at operating temp. while stopped after getting off the interstate.
Idle would fluctuate between 500RPM and 1500 RPM on cold start.
I cleaned the idle motor; that did not fix the problem.
Adjusted throttle body per instructions and that did not work.
Replaced TPS; that did not work.
In desperation, I disconnected the idle motor and adjusted the idle to get a ‘good’ idle with engine hot. Drove car for three weeks with idle motor disconnected, idle was good when hot. Idle would occasionally fluctuate, not as bad as before. This gave me an idea, problem must be a vacuum leak. I checked all vacuum lines and connections they were all good.
Only other source of vacuum leak was the vapor canister purge solenoid. Disconnected and plugged both ends; idle is stable now. Drove car for one week like that. Idle was beautiful, actually brought tears to my eyes! Reconnected idle motor idle is still stable at 900RPM, I will try to adjust down a bit.
I hope this helps you guys. I know some of you have removed your emissions equipment (i.e. vapor purge solenoid/canister) but look for a vacuum leak.
Looking at the design of the idle control valve, I also think it might be possible to open the valve with just the manifold vacuum. A weak spring in the valve or a high manifold vacuum could cause this.
I hope this helps!
All hail ,Freakazoid the conqueror !
Idle would stick at around the 1500 RPM with engine at operating temp. while stopped after getting off the interstate.
Idle would fluctuate between 500RPM and 1500 RPM on cold start.
I cleaned the idle motor; that did not fix the problem.
Adjusted throttle body per instructions and that did not work.
Replaced TPS; that did not work.
In desperation, I disconnected the idle motor and adjusted the idle to get a ‘good’ idle with engine hot. Drove car for three weeks with idle motor disconnected, idle was good when hot. Idle would occasionally fluctuate, not as bad as before. This gave me an idea, problem must be a vacuum leak. I checked all vacuum lines and connections they were all good.
Only other source of vacuum leak was the vapor canister purge solenoid. Disconnected and plugged both ends; idle is stable now. Drove car for one week like that. Idle was beautiful, actually brought tears to my eyes! Reconnected idle motor idle is still stable at 900RPM, I will try to adjust down a bit.
I hope this helps you guys. I know some of you have removed your emissions equipment (i.e. vapor purge solenoid/canister) but look for a vacuum leak.
Looking at the design of the idle control valve, I also think it might be possible to open the valve with just the manifold vacuum. A weak spring in the valve or a high manifold vacuum could cause this.
I hope this helps!
All hail ,Freakazoid the conqueror !