A/c my engine stalls while in idle when I turn on the a/c, but does not when I'm driving. what is the problem? please help

The idle is controlled by the engine computer and it is not adjustable. Do the following if you have idle problems.

Here are the most common causes of idle surge, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake

Robert, You may have to try this relearn procedure.
Warm the engine, but hold your foot on the throttle as necessary to keep the engine running.

1. With vehicle in Park, slowly release the throttle so that the engine will idle on its own. You may have to work at this a bit.
2. Let the engine idle on its own for about one minute.
3. Continue to let the engine idle and with your foot on the brake, place the transmission in Drive and let the engine idle for another minute.
4. Continue to let the engine idle with your foot on the brake and the transmission in Drive. Turn the A/C on and let the engine idle for another minute with the A/C compressor running.
5. Turn the ignition off and wait a minute. Check the attached links,
   "I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info."

Battery Disconnect or Replacement Problems

https://ca.answers.yahoo.com/question/index?qid=20100517211203AAw91qa

http://www.automotiveforums.com/t454660-click_here_for_instructions_on__quot_how_to_idle_relearn_quot_.html

The Dodge Relearn Procedures eHow

It can be low fuel pressure issue or clogged fuel pump. Or its engine related issues,---------------

Check the help link mentioned below to troubleshoot the problem: ------

Engine stalls when gas is given?

http://technoanswers.blogspot.in/2012/01/engine-stalls-when-gas-is-given.html

-------------

Car stalls when MAF sensor is connected?

http://technoanswers.blogspot.in/2012/01/car-stalls-when-maf-sensor-is-connected.html

------------

Car Engine Stalls While Driving?

http://schematicsdiagram.blogspot.com/2011/12/car-engine-stalls-while-driving.html

--------------

Car stalls and throws white smoke from exhaust?

http://repairhelpcenter.blogspot.com/2012/01/car-stalls-and-throws-white-smoke-from.html

-------------

Stalls And Dies At Stop Sign?

http://www.howtobyme.blogspot.com/2012/07/stalls-and-dies-at-stop-sign.html

------------

GMC Sonoma Stalls and idles low

http://technoanswers.blogspot.com/2012/10/gmc-sonoma-stalls-and-idles-low.html

------------

Nissan Pathfinder stalls and bucks on Acceleration?

http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html

-----------------

1992 Chevrolet stalls and shutdown?

http://schematicsdiagram.blogspot.in/2012/04/1992-chevrolet-stalls-and-shutdown.html

------------

Stumbling and stalling at idle after engine rebuild?

http://schematicsdiagram.blogspot.in/2012/03/stumbling-and-stalling-at-idle-after.html

--------------

1990 mazda 323 stalls and quit running?

http://technoanswers.blogspot.in/2012/02/1990-mazda-323-stalls-and-quit-running.html

-------------

2000 Toyota Camry: Idling and Stalling Problem?

http://whatisbyme.blogspot.in/2012/05/2000-toyota-camry-idling-and-stalling.html

---------

1995 Toyota Corolla: Stalls, Sputters and Pops Through Intake Manifold?

http://whatisbyme.blogspot.in/2012/05/1995-toyota-corolla-stalls-sputters-and.html

----------------

1999 Toyota Camry: Erratic stalling and high engine RPM at idle?

http://whatisbyme.blogspot.in/2012/05/1999-toyota-camry-erratic-stalling-and.html

--------------

Dodge Dakota stalls, stumbles at idle. Has low fuel flow and runs hot?

http://schematicsdiagram.blogspot.in/2012/03/dodge-dakota-stallsstumbles-at-idlehas.html

--------------

1994 Toyota 4Runner: Stalls and Stops While Driving?

http://whatisbyme.blogspot.in/2012/05/1994-toyota-4runner-stalls-and-stops.html

---------------

1997 Toyota Camry: Erratic Idle and Intermittent engine stalling?

http://technoanswers.blogspot.in/2012/04/1997-toyota-camry-erratic-idle-and.html

-------------

Ford Maverick: No Idle and Stalling issues?

http://schematicsdiagram.blogspot.in/2012/04/ford-maverick-no-idle-and-stalling.html

-------------

These details will help.

Thanks.

It can be low fuel pressure issue or clogged fuel pump.Or its engine related issues,---------------
Check the help link mentioned below to troubleshoot the problem :------

Engine stalls when gas is given?

http://technoanswers.blogspot.in/2012/01/engine-stalls-when-gas-is-given.html

-------------

Car stalls when MAF sensor is connected?

http://technoanswers.blogspot.in/2012/01/car-stalls-when-maf-sensor-is-connected.html

------------

Car Engine Stalls While Driving?

http://schematicsdiagram.blogspot.com/2011/12/car-engine-stalls-while-driving.html

--------------

Car stalls and throws white smoke from exhaust?

http://repairhelpcenter.blogspot.com/2012/01/car-stalls-and-throws-white-smoke-from.html

-------------

Stalls And Dies At Stop Sign?

http://www.howtobyme.blogspot.com/2012/07/stalls-and-dies-at-stop-sign.html

------------

GMC Sonoma Stalls and idles low

http://technoanswers.blogspot.com/2012/10/gmc-sonoma-stalls-and-idles-low.html

------------

Nissan Pathfinder stalls and bucks on Acceleration?

http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html

-----------------

1992 Chevrolet stalls and shutdown?

http://schematicsdiagram.blogspot.in/2012/04/1992-chevrolet-stalls-and-shutdown.html

------------

Stumbling and stalling at idle after engine rebuild?

http://schematicsdiagram.blogspot.in/2012/03/stumbling-and-stalling-at-idle-after.html

--------------

1990 mazda 323 stalls and quit running?

http://technoanswers.blogspot.in/2012/02/1990-mazda-323-stalls-and-quit-running.html

-------------

2000 Toyota Camry: Idling and Stalling Problem?

http://whatisbyme.blogspot.in/2012/05/2000-toyota-camry-idling-and-stalling.html

---------

1995 Toyota Corolla: Stalls, Sputters and Pops Through Intake Manifold?

http://whatisbyme.blogspot.in/2012/05/1995-toyota-corolla-stalls-sputters-and.html

----------------

1999 Toyota Camry: Erratic stalling and high engine RPM at idle?

http://whatisbyme.blogspot.in/2012/05/1999-toyota-camry-erratic-stalling-and.html

--------------

Dodge Dakota stalls, stumbles at idle. Has low fuel flow and runs hot?

http://schematicsdiagram.blogspot.in/2012/03/dodge-dakota-stallsstumbles-at-idlehas.html

--------------

1994 Toyota 4Runner: Stalls and Stops While Driving?

http://whatisbyme.blogspot.in/2012/05/1994-toyota-4runner-stalls-and-stops.html

---------------

1997 Toyota Camry: Erratic Idle and Intermittent engine stalling?

http://technoanswers.blogspot.in/2012/04/1997-toyota-camry-erratic-idle-and.html

-------------

Ford Maverick: No Idle and Stalling issues?

http://schematicsdiagram.blogspot.in/2012/04/ford-maverick-no-idle-and-stalling.html

-------------
These details will help.
Thanks.

Vehicle starts but stalls.These types of problems are very common on most of vehicles.There are few possibilities,that can cause stalling problem on vehicle.The vehicle brand and model may differ but problem is same.------I provide you few suggested help link to troubleshoot these issue and solve the problem:-----------
1995 Toyota Corolla: Stalls, Sputters and Pops Through Intake Manifold? http://whatisbyme.blogspot.in/2012/05/1995-toyota-corolla-stalls-sputters-and.html
-------------1994 Toyota 4Runner: Stalls and Stops While Driving? http://whatisbyme.blogspot.in/2012/05/1994-toyota-4runner-stalls-and-stops.html
-----------1992 Chevrolet stalls and shutdown? http://schematicsdiagram.blogspot.in/2012/04/1992-chevrolet-stalls-and-shutdown.html
-----------Dodge Dakota stalls, stumbles at idle. Has low fuel flow and runs hot? http://schematicsdiagram.blogspot.in/2012/03/dodge-dakota-stallsstumbles-at-idlehas.html
------------Engine stalls when gas is given? http://technoanswers.blogspot.in/2012/01/engine-stalls-when-gas-is-given.html
------------1990 mazda 323 stalls and quit running? http://technoanswers.blogspot.in/2012/02/1990-mazda-323-stalls-and-quit-running.html
------------Nissan Pathfinder stalls and bucks on Acceleration? http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html
------------Car stalls when MAF sensor is connected? http://technoanswers.blogspot.in/2012/01/car-stalls-when-maf-sensor-is-connected.html
-----------Car Engine Stalls While Driving? http://schematicsdiagram.blogspot.com/2011/12/car-engine-stalls-while-driving.html
--------- Stalls And Dies At Stop Sign? http://www.howtobyme.blogspot.com/2012/07/stalls-and-dies-at-stop-sign.html

-----------
These are few help links,that will help you to troubleshoot the issue and solve the problem.Please keep updated,if any more help required.Thanks.

Read the following and follow the instructions for this problem.

Here are the most common causes of idle surge, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake

this is caused by slow engine idle speed, do the procedure below.
Here is the common cause of surges, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

Do this.
Here are some of the causes of surges, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

Here is the most common cause of surges and stalls at stops and low erratic idle speed and rough idle, it is the idle speed control air-bypass valve and throttle valve (IAC for short), they get full of gunk over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

Often when the battery is disconnected or replaced the computer will lose it's learned idle settings. You could try letting the engine idle in park until the engine temperature comes up to normal and leave it like that for a few minutes, then put the Air con on and let it idle again for a few minutes, then switch the air con off and put it into drive. If it does not stall, let it idle in drive for 2 minutes or so, and then do the same with the Air con on. This should relearn the base idle settings and stop it from stalling on you. Before you carry out this procedure you should make sure that when you replaced the battery you didn't remove any other plugs or knocked anything that may be causing the fault. If you try this procedure and it still stall when you select drive, you will need to get a Mechanic to check the vehicle over.

Hope this helps,
Mark.