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Possible fouled spark plugs. If new plugs will start it and it drives, you still need to figure out what fouled them. This has happened to me before.
 

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I have an 01 firebird. Ran a little rough but always started, the only code I saw with my scanner was a misfire code. Then today it just died while I was driving and I had to leave it in a parking lot!!! I can hear the fuel pump kick on, and it cranks and "starts" for about 2 seconds, then nothing. Doesn't matter if my foot is on the gas. I'm now carless and I have 24 hours to pick it up from the parking lot I left it in. What could it be???
 

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The starts and runs for a couple of seconds then dies is a symptom of the lack of a 50 hertz fuel enable signal. This signal comes from BCM and goes to PCM. Without the 50 hertz fuel enable signal, pcm will apply injector ground until car runs. Then will not supply ground because of lack of 50 hertz fuel enable signal, or messed up fuel enable signal.

The fuel enable signal is part of the vats security system. So I must ask, is your security light coming on when you turn key on, then staying on instead of going off after a few seconds? If yes you have a vats security problem.

Even if security light is cycling on then off normally, you could still have a problem with the 50 hertz fuel enable signal. I learned the lesson last summer on my 90 f-body. The security light only comes on if there is no 50 hertz fuel enable signal. If signal is wrong voltage and waveform, like my 90, security light does not light.

It took one of those $70 pc based oscilloscopes to diagnose my problem. The fuel enable signal was being sent out, however it was the wrong voltage and had a crazy waveform. The correct signal should be a nice rectangular waveform, occurring 50 times a second.
 

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1994 Firebird Formula 381ci LT1 / TH400+GV O/D
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A quick PCM scan for trouble codes is always a good idea. For example, if it is a problem with the fuel enable signal not reaching the PCM, you will see P1626 or P1629. Typical start, stall with P1626 present is indicative of the fuel enable signal being lost before the correct key resistance is sensed. But that condition will also inhibit the starter.
 

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Ramblin' Wreck
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Put a fuel pressure gauge on the fuel rail connector. Sounds like the fuel pump is weak or you are out of gas. Pressure at prime should be 48-55 psi. Watch it to see if it stays up for a while.
 

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Heat is the enemy of solid state electronics. Exposed to the heat in the engine compartment, any flaw in said semiconductor will cause it to break down eventually.
 

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I have a 2002 Firebird with the 3.8 in it. A week ago it started stalling out and gave a PO174 code. I pulled the MAF and cleaned it with electronics cleaner and drove it for a little bit. It stalled and would not start back. I have since replaced both O2 sensors and the fuel filter. Now it starts but a few seconds later it stalls out without setting any kind of code.
 
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