What causes a truck to stall at idle?
Cleaning and/or making an adjustment to the throttle body may correct the problem. Engine running at idle, plug the IAC passage, and the RPM (revolutions per minute) should be at or near 400 rpm. A vacuum leak present could also cause the engine idle to be improperly controlled and needs to be identified before any adjustments are made.
Can a bad throttle position sensor cause idle surging?
Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges. 3) Check Engine Light
What does it mean when your car idles for a long time?
The idle of a car engine is kind of like a human heartbeat: You can tell what shape it’s in just by listening. Problems with idle speed —things like slow idle, fast idle, rough idle, or stalling after idling for a few seconds—are symptoms that something is wrong with your engine.
Why is idle speed not coming back up?
If the ISC system is working correctly, the PCM should adjust idle speed to keep the engine from lugging down when the A/C compressor engages. If idle speed drops down and does not come back up, the ISC system is not responding the way it should.
Why does idle RPM drop from Park to in gear?
A large drop from Unloaded to In-gear idle setting can otherwise usually be attributed to either a vacuum leak or a convertor that’s to ‘tight’ for the engine set-up I agree with John. I also believe the initial 22° timing is too much, more like 12°. Tune carb with a vacuum gauge at a lower curb idle.
What causes an engine to stall at idle?
If the ISC valve is gummed up with fuel varnish or dirt, it may stick, preventing the engine from maintaining the proper idle speed when the throttle closes. A faulty idle speed control circuit may also allow the engine to stall when idling if it fails to compensate for idle loads placed on the engine by the charging system or A/C compressor.
Why is my car running low at idle?
If the timing is falling way back in gear, that’s most of your problem. Usual culprit is a centrifugal and/or vacuum advance kicking in at idle. As soon as you throw it in gear it drops back, making the RPM drop worse than it would ordinarily be. Also check for vacuum leaks.
Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges. 3) Check Engine Light