Why does it stall after it is warmed up?

Hi maz. Here's a link to a troubleshooting guide to stalls that includes warm engine stalls. Hope it helps, good luck! http://autorepair.about.com/cs/troubleshooting/a/bl303b.htm

check the fuel pressure first, these systems typically required 50psi or greater for proper fuel injecter operation. if pressure is good with key on/ engine off, (fuel pump is cycled up), then check at idle, gradually increasing engine speed. if pressure starts to trail off with speed then look for a fuel line obstruction first (dirty fuel pump?) if that does not correct the problem, then the fuel pump is most likely failing

2000 Grand Prix GT 3.8 non-supercharged engine was randomly stalling when at operating temperature, at any speed, at any rpm, or idling. Ran well when it ran, but RPMs would randomly drop to zero and the engine would stall. Worsening occaisional no-start condition with no spark. All power in the vehicle remained on. Sometimes would start right back up and other times would not start for 3-30 mins. No check engine light and so no codes to pull. No traction light issues which sometimes occur when the crankshaft position sensor is failing. I didn't want to change the crankshaft position sensor because, quite frankly, it sucks. Changed the ignition control module. No change. Changed plugs and wires with no change. Finally decided to change the CPS. After much research and finding conflicting information I compiled a procedure with just the truthful parts I found and it worked beautifully and the car runs perfectly now. The CPS on these cars fail. If you have decided to change yours out it is a $35 part and is DIY with the proper information, which follows, some ingenuity, and some mechanical apptitude: Jack and secure car. Remove passenger side tire and the plastic wheel well. The clips will probably break, so buy new ones at a hardware store later. Number and remove spark plug wires from the ignition control module so the car won't start. Remove the center bolt (15/16th inch head) from the harmonic balancer. Easiest way to do this without a doubt is to postion a flat wrench on the bolt, rest the boxed end of the wrench on the car frame in front of the harmonic balancer, and tap the starter. Remember to disable the car from starting. Bolt will break loose. To pull off the harmonic balancer use a standard harmonic balancer puller, but you will need special grade 8 bolts and washers. 1/4-28 bolts, 3" long, one inch of thread is o.k. Place a short 3/8" extension in the crank bolt hole to protect the threads. Carefully, by hand, thread the specialty bolts through the puller and into the 3 holes on the balancer that seemingly have no threads. The threads are farther in and not visible. Make sure the bolts are straight, and inserted to an even depth into the harmonic balancer. Use washers or the bolt heads will gouge and pull through the puller. I turned my specialty bolts 15 quarter turns into the harmonic balancer. Turn the puller's main bolt that it is pushing on the 3/8"extension you placed in the crank bolt's hole. Balancer came right out/off. Remove crankshaft position sensor shield. Mine was plastic. Spread the teeth that connect the shield to its bolts with a small standard screwdriver and pull/pry just a bit. No reason to remove the shield from the bolt farthest towards the rear of the car. You'll be using thread glue on the main bolt when you put in in so you can use some of that on the shield where it connects if you mess up the plastic teeth on the shield a bit. Remove the old sensor's two bolts, and save the part to torture in fire later. Bolt in new sensor, replace shield. Line up the harmonic balancer with its cotter key deal and start pulling the balancer back on with a torque wrench. To keep the engine from turning open the smalll access hole to the flywheel on the bottom of the car (two bolts). Place vicegrips on the flywheel or wedge something in the teeth. Tighten your glued main bolt to 112 lbs plus 76 degrees. You now have a car you can count on and need not worry about it dying while driving down the road. I love mine now. Just wish someone would have made these all inclusive and accurate directions for me.

Try cleaning the throttle body this will cause a stalling problem and if it's really dirty a no start also.

check your pcv valve. i can make your car stall at warm idle if its bad.

I have a 97 pontiac grand prix supercharged 3.8... I have replaced the fuel pump and the fuel filter and it still stalls and I have no idea why.. does anyone have any ideas on how to fix or what is going on??

EGR ??? I've had a few cars with an EGR but usually before the car warms up completely

RE: 2002 Pontiac Montana with 3.4 Mine randomly died or would not start just as sylvester2000 describes above AND DOES NOT THROW A CODE as he mentions. Had the fuel pump replaced for big bucks. No change. I had the CPS changed for about $100 and after taking it on a long drive through eastern Oregon have to conclude it is fixed. T H A N K Y O U !!!

It sounds like a fuel pressure issue like I was having. If you do some searching on Youtube on there are a lot of videos out there about the fuel pressure issue on fuel injected vehicles. There is a valve, almost like a tire style up toward the firewall side of the vehicle and on top near the injectors. It is possible to attach a free rented gauge from AutoZone to test it.. Now comes the hard part. How do you improve the pressure if it is too low? The typical options are: A) Fuel Pump Replacement B)Fuel Regulator Replacement C) Clogged Injector cleanouts. Last but not least, like mine if you have a physical hole in the gas tank or along the seam of the tank, it can cause the pressurized tank to not build up enough pressure to run the modern day fuel injected systems. So, you either go to AutoZone and buy the fuel tank glue for a temp fix or a junk yard and get a used tank or pay through the nose for a new one. If I had it to do all over I would get a mechanic to do the pressure testing sooner rather than later. They have ways of pumping air into the gas tank and adding dye so that if there is a leak the red dye comes out in a visible gas form. If budget will not allow you to hire a mechanic, then find a friend who is willing to change the gas tank, fuel pump, and possibly the fuel pressure regulator on the fuel rail. The videos on line will help you with each potential job.

Geez ... I have a 2002 Grand Prix and it took less than a hour to change the Fuel Pump ... one of the easiest jobs there is to do . Fold down the rear center cup rest ... push the small barrier to gain access to the trunk ... lift the carpet, remove about 8 self tapping screws and Presto ... there is the fuel pump assembly ... one bolt ,, 3 push on connectors a couple plugs to pull out ... one/half turn and the complete assemble (tank level and all) is in your hand .... took me longer to find the right size tools then to do the job

I know you posted this quite awhile ago sylvester2000, but quick question. ...do you recommend having a mechanic change the CPS or is it something a somewhat novice like me can handle? My 2002 grand prix supercharged does exactly what you described, in fact you might as well bwen talking about my car. You gave great instructions on how to change it I just don't want to make it worse. Thanks for your help!

2002 Pontiac Grand Prix Super Charge 3.8L I'm purchasing from my friend, and it tends to sputter then stall when it gets cheap gas or gets warm. Now the cheap gas I can figure out. But the fuel pump, The mass flow and air filters have all been replaced. I am looking into flipping the car for quick sale so buy a more economical vehicle..(As I don't need the tickets.) I have put fuel booster and injector cleaner in the tank but lost the only key. So now, having to have a new key made, I am hoping that it is only dirty injectors. No dash lights come on to signify any issues so I am told that it's likely not an electrical issue. If anyone has any further suggestions please fill me in. Thank You All.

Everybody I was having all these problems with my 1993 grand prix se and it was all due to my coil pack not tight enough so wasn't making a good ground tighten it and runs better then when I got it ..............

Just to put this out there. I have a 2008 Pontiac grand prix. When put in reverse, car stalled. Baffeled I put in a new fuel pump (127,000 miles on car was gonna fail at some point anyway,236.00). Same problem. Put on new crank position sensor (I've had them fail). No fix. I had got a code about the accelerator pedal position sensor (fly by wire) but just cleared the code. Suspected the ECM. Un pluged a few sensors and it set codes. Cleared them. Followed the ecm wiring harness and noticed where it had been rubbing the valve cover. Took a mirror and looked under it and saw bare wire. Unwrapped the harness and found two broken rubbed thru wires. Butt spliced them back together and fixed. Please note. I am a do it yourselfer based on the fact the most people cannot fixe but yet charge you way to much to find, fix a problem. My local dealer waould have maybe found the problem, but still charge me 2000.00. Be ware of them people. A little looking around or talking to a friend can save you a lot of money. By the way, I have nothing good to say about any dealership repair shop.However, they could change their reputation by lowering their shop rate from a rediculas 100.00 an hour to the rate of what they pay their people plus a small fee.

I have a 2008 Pontiac grandprix and it’s does some crazy stuff it will crack then die out and then don’t wanna crank back up right then but later on it cracks again does abody know what’s going on with this car I done fix so many things and had it tested it wasn’t a fuel pump problem or Alternator problem no codes are reading so I’m just trying to find out what’s going on here