the car use to warm up to 3000 then drop to 1500 rpm but lately when i start it cold it just goes up to 1500 then down to 750 or so. i read up that the BACV controls this but is there anyway of telling if the bacv is bad?

any input or suggestions would be apprecited, thanks

jimmy

 

Without any vehicle information provided, I'll assumed 2nd gen.

The BAC and Air Bypass Solenoid Valve supply additional air on start-up for ~17 seconds. If the car is started in gear, or if the coolant temperature switch on the bottom of the radiator is bypassed, it will skip the 3k RPM warm up. This is a good thing. The 3k RPM start is just to warm the precats for emissions purposes.