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Forum namePerformance/Engine
Topic subjectIdle issue while A/C is on.
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=117491
117491, Idle issue while A/C is on.
Posted by freelancefool, Sep-27-07 05:55 PM
After doing my manual transmission problem I have this weird idle issue. As long as the A/C is on and the car is rolling, my car idles around 1600-1900 rpms. Say I drop the car into neutral while rolling to a stop in traffic, the rpms will not drop until I come to a near complete stop. Less than 5mph.

This only happens with the A/C on and the car is moving. If I turn it off, the car idles normally. If I am sitting at a stop and turn the A/C on, the rpms rise to about 800-850 and stay.

I'm kinda confused as to what is going on here and I am not really sure where I should start.

Thanks for the input.
117492, RE: Idle issue while A/C is on.
Posted by DR1665, Sep-28-07 04:27 AM
It's typical. Since Daisy was new, clutch-in coasting to stops has been around 1500-1900rpm, especially when the engine is on. Disconnect your VSS and watch it stop. The ECU is using VSS signal to determine the car is still moving and keep engine speed up in case you need it.

Who knows why it does this. It just does.

EDIT:
Meant to say "especially when A/C is on," but it's funny enough that I'll leave it...
117493, RE: Idle issue while A/C is on.
Posted by DarkOne, Sep-28-07 06:50 AM
Originally posted by freelancefool
Say I drop the car into neutral while rolling to a stop in traffic, the rpms will not drop until I come to a near complete stop.


Normal... they all do that.
117494, RE: Idle issue while A/C is on.
Posted by RoninEclipse2G, Sep-28-07 07:38 AM
It's just the ecu adjusting for the extra drag the AC is causing, perfectly normal

quit dropping into neutral, you're wearing your brakes harder than necessary.
117495, RE: Idle issue while A/C is on.
Posted by freelancefool, Sep-28-07 04:31 PM
Thanks. I was just hoping that it wasn't something unusual since the car runs great. Thanks for the replies.

Originally posted by RoninEclipse2G
It's just the ecu adjusting for the extra drag the AC is causing, perfectly normal quit dropping into neutral, you're wearing your brakes harder than necessary.


Pssh. I've got 151K miles on the stock rotors and the second set of pads. I need new rotors and pads.
117496, RE: Idle issue while A/C is on.
Posted by twack, Dec-08-07 12:07 PM
sounds loike a bad alt or a your engines tired and old