FIXED!! READ ON!!

First off, I originally had a thread that said...Troubleshooting HELP!!! (Fuel issue...possible fuel pump????HELP)Fuel issue...possible fuel pump????HELP, but to simplify things here goes and thanks for all the previous help.

I have changed the fuel filter, fuel pump, fuel pump relay, fuel pump regulator, EGR, IAC and the spark plugs...and my car will start up fine. After a few minutes it will just sputter and then just shuts off. I can pump the gas a try to keep it running...to no avail. What should I check next? I have already lost all my patience.

Also, the TCS light does not come on, theres no problem with tach, it does not have a resistor (its a GT) and the CPS was new when the motor was installed in December.

Please help...I was thinking MAF, but I don't need to spend anymore on a guess. $700.00 and counting with no fix

Well....We have a local member that has the same issue come up at times. Only issue is that his car literally wants to idle at 2500 rpm. I've read that if the MAF reads an incorrect amount compared to what the O2 value is, it can cause the engine to shut down. It could possibly lead to a vacuum leak, but we've checked and checked and double-triple checked. The only thing I can think of is tearing the top of the engine off, and replacing all the upper gaskets.

I should also say, we've replaced all the sensors on top except for the MAF, pulling the resistor out does no good. You can watch the fuel pressure just die right off...so something is telling it to shut the pump off.

Now that weather is permitting, we're gonna dive into this and get to the bottom of it.

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GreenBastardPerformance2000 GTP Coupe (the green bastard)
XP, Pacesetters, LS1 TB & MAF,MSD System, P&P LIM, P&P GenV w/ 3.2, 3.0, 2.8, Devil'sOwn Injected 100% Methanol,PowerTuned, TripleEdge Trans w/3.29's
12.92 @ 105mph

What you are describing sounds like an issue with the CPS. You got the remember that the CPS is a two segment sensor. One part controls the tach signal and thus has a play in TCS, the other controls the spark. When I replaced mine last, for the second time, in January I too did not have any TCS indications or Tach indications. However, I could idle the car then after a few minutes it would just die and would not restart right away. The first time it was replaced, it would stumble a bit and I MIGHT loose the tach and TCS and it would keep on going. Occasionally it would just outright die or stall on me but it would start back up fairly quickly.

The one way to prove it is the CPS is to let it idle until it dies. Then pull the #1 plug off at the coil pack end. Stick a screw driver up into the boot so that it make contact with the metal clip. Then with the help of a friend, spouse, etc, have them get in the car and try and start it. You'll want to hold the metal part of the screwdriver close to the coil pack terminal and see if it is getting any spark. Obviously you dont want to be touching the metal of the screwdriver with your hand unless you like that sorta thing.

If you are not getting any spark there then I feel confident in saying the issue is likely the CPS. Ive put two of those things on my car in the past 4 years. I certainly understand your frustration, trust me I do. You've spent all this money and are no better of as a results. But do this bit of troubleshooting so that we can rule out the CPS for sure. After that, with all the work you have done, there isnt much else to check and my next step would be to look at the MAF. Because you did not mention it Im going to assume there are no codes or SES light.

You'll have to bear with us as troubleshooting with only text is a challenge to say the least unless someone here has had the exact same problem. We dont get to hear how the car runs when it does, we dont get to hear how it dies, we cant hook a laptop up to it or a scan tool and so on. Look at it like this. You arent going to have to worry much about anything once you get it running, its all been replaced.

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Scotty Hall
Bartlesville, OK
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it.

The only limitation you will ever face in life is yourself!

Thanks for the help...I will check the CPS this weekend. It was new with the engine in Dec. but that doesn't mean very much.

Also, I was reading somewhere about the EVAP canister. I started messing with the EVAP solenoid (purge valve), when I disconnected it the car ran ok for a couple of minutes, I unplugged it, disconnected the hoses and it didn't seem to make much of a difference. But the solenoid felt like it was turning on and off randomly (when plugged in). When I blocked the hose (the one beside the coils) it shut the car down quick. But the car would run with this entire piece unplugged and disconnected. It eventually died.

Could this be a possible problem?

Also, I didn't mention it earlier but there are not SES lights and I have checked every fuse possible.

Once again thank you for the help...I'll keep it up

if the evap was an issue the ses light would come on. We eliminated the pcm before didn't we?

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Steve
'97 GTP VS cam, ZZP PCM, and not much else yet

Yeah, keep in mind with most emissions related stuff, that SES light is going to come on in a hurry. If you get close enough to the EVAP solenoid you can hear it pulsating when the engine is running. I too wasnt aware that they worked that much either.

I have filled my gas tank to such a degree that it has caused stumbling, rough idle and for it to stall on occasion, but that usually clears up with a couple miles of driving.

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Scotty Hall
Bartlesville, OK
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it.

The only limitation you will ever face in life is yourself!

It appears to be FIXED! As anyone that has read this knows...I changed the following in this order:

Fuel Filter
Fuel Pump
Fuel Pump Relay
Spark plugs (AC Delco Iridium)
Fuel Pressure Regulator
Checked fuses, hoses, connectors
EGR
IAC
EVAP Solenoid
EVAP Purge Valve
and last but not least the MAF...and guess what...it appears to run fine (slightly rough idle)!

I test drove it and other than waiting for something to go wrong and listening to every little rattle and hum, etc. It drives fine now...other than I think the
new plugs got fouled up during the attemped fix. Just from idling in the driveway before I changed the MAF they turned black and chalky. Should I change them, clean them or will they clear up now that I'm running?

Thanks for all the help and I hope this ridiculous pain in the *** will help someone out in the future.

if they are real black I would change them out, they should eventually clean up, but you may have problems before that happens (and they are cheap)

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Steve
'97 GTP VS cam, ZZP PCM, and not much else yet

Makes me wonder if this is my problem.... time to invest in a new MAF

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2002 GT...Wizardair, ZZP 2.5 o/r dp, Special Eddition two-tone leather interior added, HUD added, 12" Brake Upgrade, ZZP strut tower bars, gmpp sway bars,-6an braided SS fuel hoses , Hptuned, Top Swaped.....
I've got Boost!! I've got only 1.5* KR left my poor L36 block.....

They would probably clean up, but I too would probably change them out. Definitely glad to see that you have it fixed and running again. I dont think I have ever run across a MAF that did that. That is definitely a unique case. I drove to Kansas a couple years ago to troubleshoot a fellow GTP owner's car. When I got hooked up, we drove around and I scanned. No hesitation, no stalling, no nothing other than more KR than I would like to see.

Upon examining and monitoring his MAF I noticed no signal was coming from it at all. It was completely fried. Swapped his out with mine which was working, drove around some more. Now I could see the MAF changing with increases and decreases in air flow and almost all the KR was gone.

Ive seen a MAF cause rough idle before but I dont recall at anytime one that would cause it to run then just die. So I'll have to make note of that.

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Scotty Hall
Bartlesville, OK
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it.

The only limitation you will ever face in life is yourself!