nattyn ... 3/27/2012
1994 Mercury Cougar XR-7 6 Cyl 3.80L
When I'm driving my rpm will rev up then go back to normal it will be fine for like week then all of sudden will do it
It will run fine then the rpm will shoot up again then b fine then do again
With this type of engine, there may be a cold advance throttle actuator. If the problem is only occuring while at idle, I would guess that your actuator is coming on when it shouldn't be, which indicates a problem in one or more of the intake air sensors. Check the engine for codes and carfully clean the MAF and BARO/Ambient Air temp senors with a lint free cloth using only water or mild soap and water.