Thread: 1999 Grand Prix gt won't start

Dont you mean 19 is crank position sensor? Not cam sensor?

Have you unplugged the MAF and tried it to see if it would run? You said you got it to run but it was rough and only when you stayed on The gas.
Your 3.8 doesn't have a belt, it has a chain. The can sensor is below the water pump right above the balancer.

If you have a good scanner you can check the correlation of can and crank sensors while its running.
My 2000 GTP was missing badly and would only run under Heavy throttle when my maf went out. My exhaust was also Glowing red all the way to the mufflers at the rear of the car.

And once you step on the throttle the IAC has no affect on the car, it ONLY functions at 0% throttle input. So that's not it.

#23 is the cam sensor. There are no knock sensors in the diagram you posted.

Yup tried unplugging it, still nothing.

19. SENSOR. Distributor (also Knock Sensor)
SENSOR,CR/SHF POSN(4 PIN)(ACDelco #213-151). BOLT-BRACKET-CLIP-CONNECTOR-HARNESS-MAGNET-MODULE-NUT-RETAINER-SEAL-SENSOR-SHIELD-STUD, Distributor (also Knock Sensor). For: W 3.8K(L36) (1997-2003) (1999 - 2003). Required: 01
SENSOR,CR/SHF POSN(4 PIN)(ACDelco #213-151). BOLT-BRACKET-CLIP-CONNECTOR-HARNESS-MAGNET-MODULE-RETAINER-SEAL-SENSOR-SHIELD-STUD, Distributor (also Knock Sensor). For: W 3.8K(L36) (2000-2005) (2000 - 2005). Required: 01

23. SENSOR. Distributor (also Knock Sensor)
SENSOR,CM/SHF POSN(ACDelco #213-346). BOLT-BRACKET-CLIP-CONNECTOR-HARNESS-MAGNET-MODULE-NUT-RETAINER-SEAL-SENSOR-SHIELD-STUD, Distributor (also Knock Sensor). For: W 3.8K(L36) (1997-2003) (1999 - 2003). Required: 01
SENSOR,CM/SHF POSN(ACDelco #213-346). BOLT-BRACKET-CLIP-CONNECTOR-HARNESS-MAGNET-MODULE-RETAINER-SEAL-SENSOR-SHIELD-STUD, Distributor (also Knock Sensor). For: W 3.8K(L36) (2000-2005) (2000 - 2005). Required: 01
SENSOR,CM/SHF POSN(ACDelco #213-346). BOLT-BRACKET-CLIP-CONNECTOR-HARNESS-MAGNET-MODULE-NUT-RETAINER-SEAL-SENSOR-SHIELD-STUD, Distributor (also Knock Sensor). For: W 3.8K(L36),3.8-1(L67) (2004-2004) (1999 - 2004). Required: 01
SENSOR,CM/SHF POSN(ACDelco #213-346). BOLT-BRACKET-CLIP-CONNECTOR-HARNESS-MAGNET-MODULE-NUT-RETAINER-SEAL-SENSOR-SHIELD-STUD, Distributor (also Knock Sensor). For: WB 3.8K(L36) (1999-2003) (1999 - 2004). Required: 01

Do we have an explanation to why it smokes so bad?

Both of the sensors are magnetic impulse sensors that read a relucter ring and send that signal to the ecm.
The knock sensors are on the lower front and rear of the block and screw into The water journals and read harmonic vibrations from the engine. They are not the knock sensors.

Its smoking probably because its running rich. Keep it running for about 2-3 minutes and look under the car to see if your pipes are glowing.

Doesn't stay running, as soon as I let off the gas it dies immediately. If it was running rich, that would be something with the air fuel mixture

Exactly. That's why I'm saying try the easiest thing first. MAF sensor. If it doesn't work you can always take it back for a refund if you buy it from a parts store. But at least you eliminated one thing.

Mine didn't clear up when I unplugged it, but it didn't seem to be as bad.

Did you unplug it with the car running or did you unplug it then try stating the car?

Make sure the ignition is off, unplug the maf then start the car. this may be a stupid question, (i mean no disrespect) but you are unplugging the right sensor arent you? The sensor on top of your throttlebody.

Ok Ill run down to the autoparts store tommorrow and grab one. Ill report back.

I Beleive I did it with the car running. Yes I pulled on the right sensor

Unplug it with the ignition off, then try starting it. Go try that real quick and report your findings.

Still didn't answer if there are any codes lol.

I Googled this.

IAC Valve and Outside Air Temperature Sensor. (plugged into the flexible tubing on your air intake box)

Just sayin.

Unplug your battery, touch your cables (positive /negative) together, clean these 2 things.

I bow down to you thom, it is the maf sensor! I realized I ply took it off with the car running, never thought that leaving it off would make a difference !

I did not know that! Thanks to all who helped, I owe you guys a beer if your ever in northern illinois

Originally Posted by Yamahakid88

I bow down to you thom, it is the maf sensor! I realized I ply took it off with the car running, never thought that leaving it off would make a difference !

So it did end up being the MAF.... Glad we could help.

K&N filter?

Before replacing it, clean it.

MAF SENSOR CLEANER or ELECTRONICS CLEANER.

Don't touch anything inside. Just spray. About a dozen quick passes.