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2004 Grand Prix - have to 'prime the pump' to start it.

newways

New member
Before I drop a couple hundred to replace the fuel pump, I thought I better check with the experts to see if anyone else has experienced this problem:

I have a 2004 Grand Prix GT2 with 150,000 miles. I consistently have to prime up the fuel pump by turning the car ON(not starting it) 2-3 times before actually trying to start it. If I don't do this, the car turns over without starting. While I'm doing this, I can clearly hear the fuel pump and I know when to try starting it by the sound the fuel pump makes when it starts to bog down as it supplies sufficient pressure. At that point, I start the car, it turns over, fires up, and runs like a champ. I can turn it off and if I start it within 30 minutes to an hour, I do not have to prime it. Any longer, say overnight, i have to follow these steps.

So far, I have replaced:
1. The fuel filter. That was my first stop because it was original. I was pretty certain that would solve the issue. I was wrong but with that many miles, it needed to be done.
2. The throttle body but that was because of a dead spot just beyond idle which almost caused me to get in an accident.
3. I've also replaced the goofy canister purge solenoid filter thing behind the rear driver fender(can't remember name) because it kept giving me a loose gas cap message.

The car is throwing NO codes and once it's running, it runs good. no hesitation, good mileage, NO problems.

Just this cold start issue.

Thanks in advance for any input and for the great forum. I've been prowling for awhile and you guys have already solved many problems I've run into.
 


has it been tuned up ever?

is it a supercharged engine? or n/a.

if n/a it could be a bad fuel pressure regulator.

you could always rent a fuel pressure tester and test your fuel pressure at the rail too. over 40 is good.
 
I tuned it up a year ago. Plugs, wires, egr, PVC, intake manifold gasket was leaking so I took care of all of that at the same time. Not supercharged and the fuel pressure regulator is part of the fuel pump assy and, from my little research, can't be replaced by itself.

Thanks for the tip though. I'm sure the local parts supplier has a fuel pressure tester.
 
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