Pontiac GP, tach to zero, traction off, engine off

[jansussie]

Have a 1998 Pontiac GP, while driving or not driving, the tach will go to zero, traction goes off, and occasionally the engine cuts off. We have replaced the ignition module, had the traction control checked, still the same problem. Repair shop recommends replacing the main computer. If we do, and it does not fix problem, the computer is ours to keep! $500 job. Anyone have any suggestions? Thanks

[BNaylor]

Your crankshaft position sensor (CKPS) is going bad. The symptoms are classic (the tach will go to zero, traction goes off, and occasionally the engine cuts off). I don't believe it's the PCM.







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.

[demonadark]

I have same problem. I bought the sensor. Where would I find good instruction on replacing it? I have the Haynes Repair manual for 1998 GP GT Thanks

[BNaylor]

Originally Posted by demonadark

I have same problem. I bought the sensor. Where would I find good instruction on replacing it? I have the Haynes Repair manual for 1998 GP GT Thanks

Just click on the following link. Its got pics too.

http://mykidz.net/GTP/CrankPosSensor.shtml

Good luck!









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]

It's not hard to replace but that balancer bolt can be a real bitch. Found that a long breaker bar also works well.

[BNaylor]

Although the procedure makes no mention of it, certain bolts should be properly torqued down with a torque wrench. The harmonic balancer bolt should be torqued to 110 lbs-ft. The two nuts that hold the CKPS to the studs should be to be torqued to 22 lbs-ft.

BTW - In metric size the balancer bolt is 28mm.









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.