Stalls when idling

check idle speed control if bad car idling low it will stall when goiing bad it goes up and down in speed idle

bad engine thermostat, seems/
heater light? are you saying the cab fan heater is poor heat.
or are you saying engine heat is slow to hit 180F+ ???????
the fan only comes on when you over heat engine.
or if A/C is on.
the fan electric on newer cars is controlled by the PCM
if the coolant never hits the programmed trip point, the fan never goes on. (bad thermostat or air in the cooling of engine block)
if coolant really is hitting say 220f, at idle or more, (fan test is in FSM read that page)
then the ECT may be fibbing. Scan it.
scan the PCM does the ECT read , true reality or not.
????
that is it.

Do the following

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

CHECK IDLE SPEED SHOULD BE 650 - 850 RPM. IF IDLE TOO LOW AC WILL PUT DRAG SLOW DOWN ENGINE CAUSING ENGINE TO STALL IF IDLE SPEED IS TOO LOW.

could possibly be the tps,or the isc,have someone check both.thats's throttle postion sensor and idle speed sensor.






Tim.............

One suggestion:
Speed sensor failure.

Info:
Some of the classic symptoms, stalling at dead stops. failure to auto lock doors. poor fuel economy. Failure to go to overdrive.


Recommendation:
Go to your local parts store and run the failure codes.

Shop notes:
Your ECU thinks that the engine is running with out moving, During slow down the engine steps down the idle to match ground speed and as a result the engine will not stall. At present it goes directly to idle and stalls due to drag on motor.
Hope this tip helps.

R/
David

THis has happened to me in the past. My fix was to clean the throttle body. The problem began after my battery died. The computer was defaulted back to its original settings after replacing the battery. Once I cleaned the throttle body, everything was fine. This happened at about 85,000 miles.

Here is the most common cause of surges and stalls and low idle 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.

Here is the most common cause of surges and stalls and low idle 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.

Here is the most common cause of surges and stalls and low idle 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.