99 GTP Quits

[muff34]

I took a Supercharged 3800 99 GTP for a test flight....WOW . Everthing is factory. 162000 km . Car runs great,however when I took it back to the dealership it Quit right where it should if it is gonna quit, at the garage. It would not start ,I tried it twice then took the keys to the salesman and said here`s your keys ,there`s the car ,it will not start .ha ha. Mechanic went out with mini computer checked for codes ,none........ the car started right up and run fine. Apparently it also happened the day before. The previous owner had it happen a month or two ago and took it too a different garage and again no codes.
When I left the dealership they were still scratching their heads(I was not there long as I was late for an appointment) I have known these guys at the dealership for years and do not question their word . My Question is has anyone had this problem and what did they find? When the car quit it did not stumble or anything ,it was just as if it was turned off . Great car would like to purchase but not if we can`t find the cure.
Thanks

[BNaylor]

Have them checkout or replace the crankshaft position sensor. The symptoms are classic of a CKPS problem. It's a common problem on '97 and up Grand Prixs. It's either ignition or fuel. Plus they can check fuel pressure just to make sure it's not a clogged fuel filter, bad fuel pump, fuel pump relays or fuel pump resistor. Good luck!

BTW - A defective CKPS may not show up on a scan or set off the SES/CEL light.






Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[stlwagon]

Could also be the MAF sensor. Just had the same problem 4 weeks ago. No codes, just died and wouldn't start.

[muff34]

Thanks for the reply guys, now for the million dollar question,are these sesors expensive? I am from Canada and realize parts are cheaper in the U.S. however I would just like to get an idea of the costs.


Thanks Again

[richtazz]

The crank sensor is relatively cheap, $20-$30 US, but the MAF sensor is expensive, $150-$175. The crank sensor is behind the harmonic balancer, and requires special tools to replace. the MAF sensor is easy to change, but will almost always trip an SES light. The other possibility is a throttle position sensor. I have had a shorted TPS cause a no-start situation on the 3800 non-supercharged, but I'm not sure if it will on a S/C engine. Have you ever ran into this on a GTP Bob?

[BNaylor]

Originally Posted by richtazz

The crank sensor is relatively cheap, $20-$30 US, but the MAF sensor is expensive, $150-$175. The crank sensor is behind the harmonic balancer, and requires special tools to replace. the MAF sensor is easy to change, but will almost always trip an SES light. The other possibility is a throttle position sensor. I have had a shorted TPS cause a no-start situation on the 3800 non-supercharged, but I'm not sure if it will on a S/C engine. Have you ever ran into this on a GTP Bob?

Hey Rich, I've seen a shorted TPS and/or MAF sensor cause a no start condition on both NA and SC 3800s. However, I agree normally a MAF sensor or TPS will set DTC error codes and trigger a SES/CEL light.

On the MAF sensor thats probably the easiest to determine bad. All you have to do is simply disconnect it. The PCM just switches to pre-programmed air flow values stored in the tables once no MAF input is detected. Plus you can operate almost indefinitely with an unplugged MAF sensor. The only side effects may be reduced gas mileage, a little erratic idle until the engine warms up, and possibly an annoying SES light. Several months back I helped a guy with a Regal GS who was dead in the water in a shopping mall parking lot on a Saturday or Sunday determine his MAF sensor was bad. He was getting ready to get it towed when I told him where his MAF sensor was located and to unplug his MAF sensor. He was able to drive it home and replaced it a few days later. See thread below.


http://www.automotiveforums.com/vbul...ght=maf+sensor


On this particular problem since it's intermittent starting and running, I'd put money on the table that it a CKPS sensor.







Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.