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Ask Reggie Whiddon Your Own Question
Reggie Whiddon
Reggie Whiddon,
Category: Pontiac
Satisfied Customers: 113
Experience:  Lead tech at river regions auto
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I have a 1997 Pontiac Grand Prix GTP and after changing my

Customer Question

I have a 1997 Pontiac Grand Prix GTP and after changing my mass air flow sensor ,throttle position sensor ,idle air control sensor ,and ignition coils my car wont start.
Can somebody tell me what's going on
Submitted: 1 year ago.
Category: Pontiac
Expert:  Reggie Whiddon replied 1 year ago.

Hello Im Reggie, do you know what the car is lacking to start, fuel pressure, injector pulse, spark? the parts you have listed affect different systems. IF your not sure a spark tester to check spark at spark plugs, if you have or can rent at autozone a fuel pressure gauge your looking for around 40 psi, if no gauge take the line loose at engine put in empty bottle and spin over for 15 seconds, you need to see at least a half pint. If you have both of those next would check for injector pulse remove a connector from one of the injectors there are 2 wires one of which is hot with the ignition switch in the run position the other is a pulsed ground from pcm they sell noid lights you plug into the connector they blink when spinning the motor over, if they dont you have no pulse and engine will not start. I dont know your tool arsenal or experience level but whatever your intentions are im here to help

Customer: replied 1 year ago.
I have spark from the ignition coils wasn't able to do the fuel pressure test but got a trouble code P1200 injector control circuit
Expert:  Reggie Whiddon replied 1 year ago.

1. Using a lab scope, check the voltage level and injector pattern at the Powertrain Control Module (PCM) connector C2 pin 22 Pink/Black wire. If there is less than Battery Voltage (B+) with the key on engine not running, check the wiring from the #3 injector to the PCM pin 22 for opens and or shorts to ground.

2. If the wire is good between the PCM and the injector but there was less than B+ at pin 22 of the PCM, check for B+ on the Pink wire at the #3 injector. If there is B+ at the Pink wire but still less than B+ at pin 22 and the wire is good between the two, the injector will need to be replaced.

3. If there is full B+ at the PCM pin 22, start the engine and monitor the injector pattern. If the pattern is erratic or no pattern at pin 22, the PCM will need to be replaced.

Expert:  Reggie Whiddon replied 1 year ago.

You most likely have a bad injector shorting the quad driver out in the pcm take a voltmeter and check the resistance of each one look for around 13 ohms measure each one and any that are even slightly out of range replace it.

Customer: replied 1 year ago.
I can't get hands on a lab scope a voltmeter may be and I have a cracked fuel pressure resistor
Expert:  Reggie Whiddon replied 1 year ago.

FuEl pressure resistor? Do you mean furl pressure regulator? So hAve to resolved your problem?

Customer: replied 1 year ago.
Behind the fender under the battery
Expert:  Reggie Whiddon replied 1 year ago.

Are you talking about the control module? I'm only asking because therr is no fuel pressure resistor. Just want to make sure you get it fixed

Customer: replied 1 year ago.
Fuel pump resistor
I have a 2speed fuel pump
Customer: replied 1 year ago.
Its on the he passaged side behind the fender under the battery
Expert:  Reggie Whiddon replied 1 year ago.

Oh aftermarket so this fixed it

Customer: replied 1 year ago.
Have to order the part but before I go order it I just wanted to know if there is a chance this may be my problem
Expert:  Reggie Whiddon replied 1 year ago.

No sir I don't think so not for that code you have. Tell me about this 2 speed fuel pump who makes it and what is its advantage over factory