Car stalls at idle with AC on
- Thread starter BraggStang
- Start date
-
Sponsors (?)
BULLITT5228
Member
When the ac is on, is it blowing cold air? You may have a blockage in the system that is causing a lot of strain on the engine. Just a thought.
Night Shifter
Well-Known Member
check your iac valve as well...mine started dieing at idle with the ac on and it turned out to be the iac valve was crapping out
wmburns
SN Certified Technician
The PCM maintains two idle trim settings. AC on and AC off. This symptom usually has three causes.
1 - AC is low on Freon and is short cycling. If the AC is short cycling, it is not running long enough to allow the PCM to re-learn new AC on idle trim values. Either fix the AC or jump the AC low pressure switch to force the AC to run for several minutes.
2 - IAC is not really functioning. Often the IAC will quit functioning for various reasons. PPL will adjust the TB throttle idle set screw in an attempt to solve an idle issue. Problem is this manual method works for certain temperatures and AC off. Low idle is the result with the AC on. Perform the IAC basic functionality tests called for in the following post.
Is your mustang stumbling, dieing at idle or idling rough? - Page 14 - Ford Mustang Forums
3 - the AC system has a problem where the compressor is taking too much horse power to spin. Some examples include excessive Freon charge.
1 - AC is low on Freon and is short cycling. If the AC is short cycling, it is not running long enough to allow the PCM to re-learn new AC on idle trim values. Either fix the AC or jump the AC low pressure switch to force the AC to run for several minutes.
2 - IAC is not really functioning. Often the IAC will quit functioning for various reasons. PPL will adjust the TB throttle idle set screw in an attempt to solve an idle issue. Problem is this manual method works for certain temperatures and AC off. Low idle is the result with the AC on. Perform the IAC basic functionality tests called for in the following post.
Is your mustang stumbling, dieing at idle or idling rough? - Page 14 - Ford Mustang Forums
3 - the AC system has a problem where the compressor is taking too much horse power to spin. Some examples include excessive Freon charge.
Mach_1_driver
New Member
I think I have this same problem. With it running rough at idle and dying when I turn the ac on. Also when I'm driving and shift to second and it gets to about 2200 RPM and higher it starts to jerk badly no to little throttle response. Also the trans feels like its burning up. It heats up the inside of the car and the shifter gets overly hot.
wmburns
SN Certified Technician
As in the above post, is your AC short cycling?
How about any vacuum leaks or exhaust leaks? What about the PVC value? When was the last time it was changed? Has the MAF been cleaned?
Have you read the information in the following post? If so, what were the results of the basic functional tests call for?
http://www.allfordmustangs.com/foru...-dieing-idle-idling-rough-14.html#post2260649
There is no elevator to success. You have to take the steps!
How about any vacuum leaks or exhaust leaks? What about the PVC value? When was the last time it was changed? Has the MAF been cleaned?
Have you read the information in the following post? If so, what were the results of the basic functional tests call for?
http://www.allfordmustangs.com/foru...-dieing-idle-idling-rough-14.html#post2260649
There is no elevator to success. You have to take the steps!
Mach_1_driver
New Member
Well I found out today the guy who had it tuned and didn't have cats on it and the Dealer put cats on it before I bought it. Basically w the tune and Headers the cats started burning up and screwed up the computer and made it act that way. Took the cats off and it ran perfect. Thanks for the info!!
Similar threads
