on dirait un probleme de Idle Air Control Valve.
C'est elle qui gere le ralentit.
Voici comment tester :
The following is based of course on a clean idle air passage as well as a butterfly that has never been tampered with....
1. Key on Engine off, place jumper wire into ALDL to put vehicle into diagnostic mode ( to check codes )
2. Go to engine bay, you will hear stepper motor moving in the IAC, remove IAC connector. At this point the IAC will be fully closed therby blocking the IAC passage and the car should not start
3a. IF CAR STARTS - Attempt to start car - if car starts and runs then there is a vacuum leak and/or tampered throttlebody and the butterfly will have to be reset.
3b. IF NO START - Attempt to start the car - If the vehicle does not start then the IAC is functioning
4. Reconnect IAC connector and remove jumper wire from ALDL and start car, there will be fluctuations in starting and even hesitation, and in some cases no start as the IAC resets itself.
This test confirms:
- That the IAC is functioning
- test for vacuum leaks
- test for a tampered throttle body