QuestionWhen cold, and after warming up, after coming off the accelerator (like slowing down to stop) the car stalls. It is like it tries to return to idle, but falls too far back and hits zero. It idles at about 800 rpm, and drops to 0 rpm when you take your foot off the gas. If you catch it before it dies, it will idle at 800, but you have to catch it.
We've tried several things, looking for vacuum leaks, fuel leaks, air leaks, etc, but have found nothing.
Any ideas?
jh
AnswerJay,
Your problem most likely lies around your throttle body area. There are many components there that should be checked.
- Throttle body [TB] (remove and clean it)
- TB air bypass valve (can be inspected when you remove the TB to clean it
- Idle Air Controller [IAC] (also referred to as the Idle Speed Controller - can be checked per a manual)
- Fast Air Idle Valve (sits below the TB; only supposed to function when engine is cold)
- Exhaust Gas Recirculation [EGR] valve (located below the intake manifold - should be clean)
- Throttle Position Sensor [TPS] (tells the computer where the throttle plate is - can be checked per a manual)
- PCV valve (valve attached to valve cover - relieves crankcase pressure)
- Engine Coolant Temp. Sensor (tells the car's computer when the engine is at 'normal operating temp.'. Once normal, the computer can regulate air/fuel mixtures accordingly)
All these items can be checked and serviced from listed procedures from a service manual. Both Haynes and Chiltons make a manual for your car that can be purchased at most auto parts stores. Diagnosing poor idle conditions is not easy because there are so many things that can be causing it. But odds are if you're able to check all the items I've listed, you'll probably find the source of the problem.
Good luck!
