Does anyone know if it's possible that a bad check valve could cause a high Idle? Also, how do you determine if the MAP sensor is working. The manual says to test for voltage with the sensor unplugged! How do you test this thing?

Clint Fralick
Struggly@hotmail.com

 

Any leak in the intake track could cause an abmnormal idle. The map sensor is most likely still good. I don't think that I have read about any bad map sensors since I've been on this forum.
A bad check valve could screw with your idle, but I would guess that it is more likely a popped hose, or bad gasket. Or, if you have added any aftermarket components, you may need to adjust your air adjustment screw. Or, it could be your fast idel cam screw out of adjustment.

 

having check valves in the wrong place can cause high idle ....