1999 Grand Am 3.4litre idle problems. Starts rough then clears out and runs fine. When car is warmed up will not idle up sometimes dies.only idles up to about 1000 rpm when cold 650 when warm. If car sets over about 5-10 minutes has to crank ecessive before it starts. Changed fuel filter, pressure reg.,throttle body,IAC,EGR and cleaned maf. HELP I AM OUT OF IDEAS!

If the start and run fine are on cold starts, I would look for vacuum leaks. The normal start mode for these things is to have a richer condition upon a cold start. When the ECU detects warmth in the engine is drops the extra rich cold start mode then the idle goes rough due to the normal mixture being too lean due to a vacuum leak. Look for cracked, loose or broken vacuum hoses. It could also be due to a EGR valve stuck open.

Dirty air filter, dirty throttle body...try 2 bottles of gas line fuel injector cleaner...has your car been parked for awhile? Heet gas additive will work on any low gas tank sludge that you may have. Hope this helps.

check vaccuum pipes may be at fault and need replacing.

Idles rough and quits when gas pedal is pressed less?
http://technoanswers.blogspot.in/2012/01/1999-ford-f-150-idles-rough-and-quits.html
---------

Rough idle, staling and Erratic shifting?

http://technoanswers.blogspot.in/2012/03/rough-idlestaling-and-erratic-shifting.html

--------

Its a hot start issue.

Can be related to low fuel pressure or problem with crank sensor.

Also it can be weak battery or starter.

But possibilities are to be inspected to confirm what exactly it is.------

To troubleshoot and confirm the issue,i suggest you refer few solved help links with similar types of problem like yours:------

Click the link below:------

1991 Toyota Trecel: Engine Starts fine but dies when gets Warm?

http://whatisbyme.blogspot.in/2012/05/1991-toyota-trecel-engine-starts-fine.html

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

1994 Toyota Pickup: Starts fine but dies in few seconds?

http://howtobyme.blogspot.in/2012/05/1994-toyota-pickup-starts-fine-but-dies.html

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

1995 Lexus LS400: Running Hot?

http://whatisbyme.blogspot.in/2012/05/1995-lexus-ls400-running-hot.html

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

2002 Toyota Camry: Puff of Blue or White Smoke while Starting?

http://whatisbyme.blogspot.in/2012/05/2002-toyota-camry-puff-of-blue-or-white.html

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

Multiple problems on car: Car runs hot, A/C blows hot and car starts surging?

http://schematicsdiagram.blogspot.in/2012/04/multiple-problems-on-car-car-runs-hotac.html

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

Delay starting on Toyota Prius?

http://schematicsdiagram.blogspot.in/2012/02/delay-starting-on-toyota-prius.html

-----------

Honda car will not start intermittently?

http://technoanswers.blogspot.in/2012/02/honda-car-will-not-start-intermittently.html

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

Vehicle Starts, Runs and Loses Power

http://whoisbyme.blogspot.in/2012/07/vehicle-startsruns-and-loses-power.html

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

Intermittent starting issues on Volvo 760?

http://schematicsdiagram.blogspot.in/2012/02/intermittent-starting-issues-on-volvo.html

-----------

Car starts and cuts off immediately?

http://repairhelpcenter.blogspot.com/2012/01/car-starts-and-cuts-off-immediately.html

-----------

Car won't start when cold?

http://schematicsdiagram.blogspot.com/2011/12/car-wont-start-when-cold.html

===========

These details will help.

Thanks.

oxegen sensor?

I just had this problem on my 1996 Jeep Grand Cherokee. Once the engine got warm, after about 15 to 20 minutes, the car would just die at random times, sometimes when doing 40 mph and sometimes at idle.

I ended up changing the Crankshaft Position Sensor and it cleared the issue.

[email protected]

try the control module

try replacing the throttle position sensor

Have you ever changed the fuel filter? If it's not that, and it's not a vacuum leak, it is probably your idle air control valve.

crankcase sensor, located behind starter on 3.5