Engine cranks and starts, but dies in minutes...

[dxpsteve]

We have been having a major issue with my 2002 Grand Prix GTP (stock).

It started under normal driving conditions when the engine completely stopped. I coasted the car to a corner, and tried to start it.

The engine cranks, and turns over, but doesn't stay started. I can get the engine to run for a few seconds by opening the throttle, but then it misfires like crazy.

We have no clue what is wrong. The only DTC's we ever get are for a misfiring cylinder.

The engine starts after sitting overnight, and even drives for a few minutes. However, the conditions have been getting gradually but noticeably worse.

We have replaced the fuel filter, and have tested the fuel pressure. Everything is ok.

We have also tested the fuel injectors, spark plugs, and coolant temperature, all are ok.

We have also observed that the car tends to die when the engine enters closed-loop.

That's all I can think of off-hand. if anybody can shine some light on our problem, it would be greatly appreciated! If you need any more information, please ask.

Thanks in advance to all.

[GaryFenza]

Fuel Pressure, Manifold Pressure?

[richtazz]

Try disconnecting the MAF sensor and see if that helps.

When you say fuel pressure is good, did you test it key-on/engine off as well as while running? Did you check it again when the car dies? Your car has a fuel pump resistor, which slows pumps operation at low engine speeds/low boost. The common symptom of a bad resistor is it will start, then die within 3-5 seconds. Since it's a resistor, this problem will first manifest after the car has run a while, as resistors build up heat over time. At the top of the GP forums is a tips and maintenance section. Follow the instructions on how to do the resistor bypass as a test.

[dxpsteve]

@GaryFenza
Fuel Pressure was fine. I don't remember exactly, but I believe it was around 44 psi. Manifold pressure is the next thing we are going to check. I will post the results.

@richtazz
Ooh, I will bring both of those up. We did test fuel pressure key-on/engine off and while running. I will check after the car dies (I think we might've done this before).

Thank you both for the prompt responses. I am working on the car with my dad, so I will let him know about these, and I'll post back.

[dxpsteve]

Originally Posted by richtazz

Try disconnecting the MAF sensor and see if that helps.

When you say fuel pressure is good, did you test it key-on/engine off as well as while running? Did you check it again when the car dies? Your car has a fuel pump resistor, which slows pumps operation at low engine speeds/low boost. The common symptom of a bad resistor is it will start, then die within 3-5 seconds. Since it's a resistor, this problem will first manifest after the car has run a while, as resistors build up heat over time. At the top of the GP forums is a tips and maintenance section. Follow the instructions on how to do the resistor bypass as a test.

Wow, thanks so much! The MAF Sensor, that's what it was. We just disconnected it, and the engine stayed on. We tested this about 3 times, just to be sure. Thanks everyone for all of your help.