erratic idle

[Dean_UK]

it seems like my AC pump is constantly clicking in and out causing the engine revs to rise and fall. it doesn't matter what setting the AC is on or whether I'm in park or drive, the idle only settles down if I switch it off completely. when sitting in the car you can hear the pump click in followed by the revs rising then a few seconds later it clicks again and the revs drop.....

oh yeah its a UK spec 1997 4.0, any ideas ?

cheers

 

[lonestar]

Originally posted by Dean_UK
it seems like my AC pump is constantly clicking in and out

You may be low on Freon. A pressure switch won't allow the compressor to run if the pressure is too low.

 

[Dean_UK]

ah, that could be it as the air doesn't get very cold.
i'll get it checked out, cheers

 

[Kamaaina]

Sounds like the Idle Air Control (IAC) valve isn't doing it's job of maintaining a steady idle while the A/C compressor cycles on and off. Does the idle speed drop when you put it in gear?

 

[Dean_UK]

i think so but i spoke to an AC company and they said it sounds like low gas so i'm gonna take it down there this week sometime..

cheers

 

[Red 97 XLT]