AC running and stalling out
Thread Starter
Cruising
Joined: Aug 2008
Posts: 10
Likes: 0
From: Raleigh North Carolina
AC running and stalling out
The basics: Stock 98 coupe with manual transmission
The background: new battery
The symptoms: 2nd day out driving around (first with AC on) and when I push in the clutch the engine RPMs drop and stalls out. Have to do a little heel-toe on the gas and brake to keep it from stalling out when coming to stops. From what I've researched on other threads in the forum an "Idle Relearn" seems to be in order.
http://www.c5forum.com/diy/idlerelearn.php
My question is, should this relearn be done while USING or Not USING the AC? It's been hotter than Haiti's here all week and I'm also concerned if the PCM is relearning air temps too, it will be set abnormally high.
The background: new battery
The symptoms: 2nd day out driving around (first with AC on) and when I push in the clutch the engine RPMs drop and stalls out. Have to do a little heel-toe on the gas and brake to keep it from stalling out when coming to stops. From what I've researched on other threads in the forum an "Idle Relearn" seems to be in order.
http://www.c5forum.com/diy/idlerelearn.php
My question is, should this relearn be done while USING or Not USING the AC? It's been hotter than Haiti's here all week and I'm also concerned if the PCM is relearning air temps too, it will be set abnormally high.
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
Once the PCM establishes the base idle RPM's, it will automatically adjust the idle RPM's, for the extra load, when the A/C is compressor is running.
Instructor
Joined: Apr 2010
Posts: 171
Likes: 0
From: Saginaw Michigan
The idle relearn that i did, was about a 20 minute process that involved the a/c being off at first, then having the a/c on for 5 minutes while in drive. It has fixed my issue of stalling out, but i also cleaned the throttle body and MAF sensor before i did the relearn.
I have an automatic, and coming to a stop the rpm's would drop below 500 and would make the engine stumble/stall. It is running really good now! Fingers crossed!
Here is the one i used.... one for auto, one for manual. I had the battery off the car for about half a day, so i didnt have to remove the fuse.
Originally Posted by Bill Curlee
AUTOMATIC TRANS:
ign. off
remove pcm batt fuse
wait 5 min
replace pcm batt fuse
a/c off
park brake and block drive wheels(do not use brake)
start vehicle
allow coolant to reach over 176F
shift into drive
wait 5 mins
turn on a/c
wait 5 mins
shift to park
wait 5 mins
turn off a/c
wait 5 mins
turn off engine. off
MANUAL TRANS :
ign. off
remove pcm batt fuse
wait 5 min
replace pcm batt fuse
a/c off
park brake and block drive wheels(do not use brake) PUT VEHICLE IN NEUTRAL
start vehicle
allow coolant to reach over 176F
then turn on a/c
wait 5 mins
turn off a/c
wait 5 mins
turn off engine for 30 secs
After you are done, take it for a good long drive(30-45 minutes) at varying speeds/rpms
I have an automatic, and coming to a stop the rpm's would drop below 500 and would make the engine stumble/stall. It is running really good now! Fingers crossed!
Here is the one i used.... one for auto, one for manual. I had the battery off the car for about half a day, so i didnt have to remove the fuse.Originally Posted by Bill Curlee
AUTOMATIC TRANS:
ign. off
remove pcm batt fuse
wait 5 min
replace pcm batt fuse
a/c off
park brake and block drive wheels(do not use brake)
start vehicle
allow coolant to reach over 176F
shift into drive
wait 5 mins
turn on a/c
wait 5 mins
shift to park
wait 5 mins
turn off a/c
wait 5 mins
turn off engine. off
MANUAL TRANS :
ign. off
remove pcm batt fuse
wait 5 min
replace pcm batt fuse
a/c off
park brake and block drive wheels(do not use brake) PUT VEHICLE IN NEUTRAL
start vehicle
allow coolant to reach over 176F
then turn on a/c
wait 5 mins
turn off a/c
wait 5 mins
turn off engine for 30 secs
After you are done, take it for a good long drive(30-45 minutes) at varying speeds/rpms
Last edited by JWAddington; Jul 7, 2012 at 09:09 AM.
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
There's no need to ever turn on the A/C during the idle relearn procedure.
The PCM is programmed to bump up the idle speed when the A/C compressor is commanded on.
The PCM is programmed to bump up the idle speed when the A/C compressor is commanded on.
Safety Car
Joined: Aug 2011
Posts: 4,449
Likes: 409
From: Portland OR
It tells the engine to produce a little more torque when the AC is on.
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