94 Jimmy, fuel pump or regulator or ???

[GT55]

First off, after the vehicle runs for a while, turn it off it won't start back up. So here is what I did. Hooked up a fuel pressure gauge at the back of the plenum. Turn the key on and listen to the fuel pump whine for 2-3 seconds. As fuel pump is whining the gauge goes to about 55-60 psi. When the fuel pump rely clicks and the fuel pump stops whining, the pressure gauge falls to about 20 psi and stays there. I split the plenum and did this test again. The pressure gauge gave the same readings and there were no leaks anywhere in the plenum.
If this is a fuel regulator problem, how can I check it? If it is a fuel pump problem, how can I check it? If it's something else please advise...

Thanks All...

GT

[GT55]

Originally Posted by GT55

First off, after the vehicle runs for a while, turn it off it won't start back up. So here is what I did. Hooked up a fuel pressure gauge at the back of the plenum. Turn the key on and listen to the fuel pump whine for 2-3 seconds. As fuel pump is whining the gauge goes to about 55-60 psi. When the fuel pump rely clicks and the fuel pump stops whining, the pressure gauge falls to about 20 psi and stays there. I split the plenum and did this test again. The pressure gauge gave the same readings and there were no leaks anywhere in the plenum.
If this is a fuel regulator problem, how can I check it? If it is a fuel pump problem, how can I check it? If it's something else please advise...

Thanks All...

GT

OK, heres a follow up. Now the pump will only run the pressure up to about 40 psi. After the rely clicks the pressure goes to near zero psi.
No leaks anywhere. Battery is hooked to a charger and is hot.

Any Help ???


Thanks

GT