Engine stalls with A/C on
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 8,550
Likes: 933
From: Communist Colorado
Engine stalls with A/C on
If I have been traveling with the a/c on, shut it down, run in a store, come out try to restart car with a/c in the on position, it wont idle. I have to keep blipping the throttle to keep it running. If I turn the a/c off before I shut the engine down, then try to restart it will start and idle fine.
Car has a cam and all supporting bolt ons and of course a tune. Whats going on here? I cant see any problems under the hood, checked my air intake connections etc.
It did this to me just after the cam was installed a couple summers ago. I figured the computer had to go through some kind of relearn sequence. It seemed ok and hasnt given me trouble until now.
Car has a cam and all supporting bolt ons and of course a tune. Whats going on here? I cant see any problems under the hood, checked my air intake connections etc.
It did this to me just after the cam was installed a couple summers ago. I figured the computer had to go through some kind of relearn sequence. It seemed ok and hasnt given me trouble until now.
Le Mans Master
Joined: Nov 2005
Posts: 6,993
Likes: 25
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 8,550
Likes: 933
From: Communist Colorado
Funny thing about it is it only happens on restart. Once I drive a few hundred yards, then come to a stop, its fine and theres no trouble. I can hear and feel the idle bump up at that time, but on restart its hard to say... its really hard to tell since it wont stay running and I have to keep feeding it with the throttle. Im not sure if its a situation of too little air or too little fuel... It doesnt happen every single time either, but today it was being a beeotch.
Drifting
Joined: Oct 2002
Posts: 1,773
Likes: 66
From: SoCal
Could have something to do with IDLE proportional or Adaptive IDLE Airflow tables. Might not have modified those when the cam was added. Quite a bit of tables in those 2 that deal with A/C off and A/C on settings. Could also be IDLE settings. Might of just added to the A/C off table some RPM but didn't add to the A/C on table. What are your RPMs in both modes?
Thread Starter
Le Mans Master
Joined: Dec 2005
Posts: 8,550
Likes: 933
From: Communist Colorado
Could have something to do with IDLE proportional or Adaptive IDLE Airflow tables. Might not have modified those when the cam was added. Quite a bit of tables in those 2 that deal with A/C off and A/C on settings. Could also be IDLE settings. Might of just added to the A/C off table some RPM but didn't add to the A/C on table. What are your RPMs in both modes?
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Intermediate
Joined: Apr 2009
Posts: 33
Likes: 0
From: Brick,New Jersey
2004 motor miss
Hi I have 2004 C5 all stock when I am at idle engine has a miss with a/c on . When a/c is off at idle no miss ,also while driving with a/c on all is good .Any ideas ? thanks Dave
Tech Contributor
Joined: Jan 2007
Posts: 19,353
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From: Dyer, IN
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,426
Likes: 3,979
From: Cape Coral, Florida
You may just have a misfire because there is a load on the engine and not because the AC is on…without a scan tool to help identify if it is a misfire you are only guessing…put a dollar bill or a small piece of paper up near the exhaust and if it get sucked in towards the exhaust pipe you have a misfire.
