Thread: 2005 Grand Prix GTP Hard Starting

Once it got cold out my GP became hard to start...it will struggle for about 5 seconds in the morning, sputter like its going to start and die out. Sometimes I need to try 3 times. After the initial hard start it is just fine for the rest of the day. I have recently cleaned the throttle body and replaced the spark plugs and wires so those can't be blamed...I checked the fuel pressure and with 0 pressure in the line it jumps to about 60 psi as soon as the key goes on, and seems to stay at 60psi while idleing. I noticed occasionally the needle was bouncing very rapidly between 55-60psi. Is this too high? Does the car even have a fuel pressure regulator?

Thanks

I was going to say to remove the throttle body completely and clean it but you have done the cleaning already.

My 06 3.8 N/A has the same issue. I notice it more when remote starting in the morning, one shot if it does not hit, then out in the cold and scraping ice.
My brother-in-law and I was discussing and we thought the pressure was leaking down over night. To test the theory the last two mornings I cycled the key on/off/on/off. Then hit the remote start and both morning it fired without issue. I will continue the next few morning to see if it was just luck these two days or a real pattern.

Originally Posted by juggernaut56

I checked the fuel pressure and with 0 pressure in the line it jumps to about 60 psi as soon as the key goes on, and seems to stay at 60psi while idling.

Is it zero because you bled the line before hooking up the tester? I am curious if you hooked the tester up at the end of the day, then started the car, shut it off, what does the pressure show overnight?

Originally Posted by juggernaut56

I noticed occasionally the needle was bouncing very rapidly between 55-60psi. Is this too high? Does the car even have a fuel pressure regulator?

Watching Car Tech, they trouble shot a fuel system that was leaking down. Basicly they suggested isolating (close) the fuel feed to eliminate the fuel pump check valve. Then isolate the return to eliminate the regulator. Then isolate both to eliminate a leaking injector.
Talking to a GM guy, I asked what fails more often, he said pull the vacuum hose on the regulator (off the top of his head) and see if it is wet. So this morning I pop the hood and could not find the regulator, did some googling and it looks like on 04+ the regulator is built into the pump. I still need to do more searching to verify 100%, unless someone here can answer that.

I am starting a thread to discuss brands/kits of "Gas Fuel Injector Tester". Once I do I will come back and edit this post with it's link for future searchers.

Which tester are you using and where did you get it?

It should stay at 65psi all the time weather idling, driving or WOT.

Jeff