Ok here's a strange one, my car idles fine when the ac/vent fan is off. But when I turn the fan on it start to bounce up and down about
200 rpm. Any ideas? I was thinking my O2 sensors or my throttle body needs to be cleaned but can't think of why it would be linked to the fan. So I'm thinking it's electrical maybe the WOT relay is toasted?Thanks Scott
Sonicmonkey opined in news: snipped-for-privacy@4ax.com:
NOw make up your mind... is this related to the fan or the A/C being on?
Remember A/C is on in the A/C, Def and Mix positions.
The WOT relay has nothing to do with it... if the comp clutch engages, it at least is good in the "off" (not WOT) position. At any rate it's probably not cycling unless your TPS is shot...so would have no effect.
Also nothing to do with O2 sensors.
My guess is your IAC is sticky and needs cleaning. Or replaced
Remember.. throttle body cleaner NOT carb cleaner.
Search this group and alt.autos.ford on google, you'll see.
I think what he is describing is when the A/C clutch engages, the engine gets 'bogged' down just a bit (200 rpms). Guess what, this is normal operation. Nothing wrong with your car.
Now, if you are trying to say that the engine idles down TO 200 rpms when the A/C cycles, then you do have a problem. Temp fix is to keep your foot on the accelerator pedal and keep the rpms around 1000-1300 rpms when you are stopped (at lights or signs).
Ah, I think some refer to is as the "blower fan under the dash".
Had a similar problem a while back. It was a bad vacuum hose.
Seems to only happen when it's in the defrost for the front window, on vent it's fine and on floor it's fine. mix it bounces to.
The Defrost and Mix settings both use the A/C which removes moisture from the air to prevent the windshield from fogging. If this lower idle condition causes stalling you may need to clean or replace your IAC.
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