Acura Vigor: when the car stars, it warms normally, when the idle settles in 1k rpm more or less.. the engine starts to rev up and down from 800 rpms to 1200 rpms.... then in aminute or less the idle settles again and then the ecu goes into backup mode...... i have tested with 3 ecus and the behavior is the same... the car starts, the idle settles, the idle goes crazy, the ecu tries to fix it, it fails to do so, and then go into backup mode.... what can be wrong??? please i need some help!!!!

 

sounds like the PCV valve problems i used to have with my nissan's.

 

Any DTCs stored? Vacuum leaks at the intake manifold gskt? Fast idle valve stuck open is fairly common?