Mysterious Loss of Fuel Pressure overnight

[neversummer]

Hello guys, and Girl.

I've seen this topic come up before somewhere, but maybe you guys have a suggestion since the dealer has their head up their You know what.. and just wants to check random things.

Hard crank over in the morning or after my truck sits a while..
6.0L 2004 Silverado. but if i let it sit on (on) position before cranking over a bit starts right up.
Hear the fuel pump whining when i turn on, and i dont have this problem once i dirve it , only if it sits for a couple hours .. and specially over night.

Starts right up if i pause on the on position for a few seconds before cranking over the starter

but if i jump in and try to start up it doesnt want to.. (pain for remote start)

Im presuming its fuel pressure regulator possibly and or somwhere on the fuel rail its losing pressure over night, is it possible a injector is leaking, where and how can i check fuel pressure at the fuel rail, can i use a tire pressure gauge?

I have already replaced the Fuel filter with a brand new Fram about a week ago.

what is optimum pressure for the fuel rail?

[GaryL]

You need a minimum of 60 psi to start. It takes a fuel pressure tester to test, do not use a tire pressure gauge. One of your local auto parts stores may loan you one

It sounds like the pump may be going out. Mine just went through the same symptoms and finally quit starting all together unless I used ether. Replaced the pump and all is well now.

[neversummer]

hummmm...
interesting, cause I have no problems with fuel pressure once its started, and or once i have started it once, it will start right up again if stopped. its only if my truck sits over night or a prolonged amount of time. I will check the fuel pressure at the rail after running it and first thing in the morning before I start it....

Am i correct in presuming that there should be fuel pressure at the rail ALL the time.

[GaryL]

There should be some pressure there, but not the full 60 psi like when the pump is running.

Just before mine died, if I was able to start it once, I could restart it multiple times. It was hardest to start in the morning, but ok the rest of the day.

[neversummer]

You need a minimum of 60 psi to start. It takes a fuel pressure tester to test, do not use a tire pressure gauge. One of your local auto parts stores may loan you one

It sounds like the pump may be going out. Mine just went through the same symptoms and finally quit starting all together unless I used ether. Replaced the pump and all is well now.

wow $158 bucks for a fuel pump, i think it works fine, I am gonna try the regulator which is only $20 first. and check for leaks around the fuel rail and make sure the pressure is up to par..

thanks

[GaryL]

Where did you find a fuel pump for $158? I just paid $220 for mine through Oreilly Auto Parts, and that was after a $56 discount.

Is the regulator external on yours or is it under the intake like the old 5.7 Vortecs like mine?

[FireRed]

You should always wait the 10 or so seconds for the pump to stop indicating the system is pressurized, being a mechanic I have done so for many years. Recently at 141,000 miles my sub starter started to act up, I pulled and tore it down to find it in near new condition inside needing only a solenoid. My last FI truck had 171,000 and never had a starter, yet you go to any electric repair shop and most people are eating starters. They have to have instant start RLOL!!!!!!!!!!!!!!!!!!!!!

[collinsperformance]

i feel good since i upgraded to a Bosh hi-pro pump for $65 at napa.
ok- your issue there is a check valve on the FMU and it is starting to go bad.....mike

[neversummer]

Where did you find a fuel pump for $158? I just paid $220 for mine through Oreilly Auto Parts, and that was after a $56 discount.

Is the regulator external on yours or is it under the intake like the old 5.7 Vortecs like mine?

Right here. a lot cheaper than the Delphi or Bosch but im sure works just as well

http://www.rockauto.com/catalog/rafr...1427565k872337