Hard Starting Due To Loss Of Fuel Pressure - Help!

[brufener]

I have a 2001 Suburban (5.3) that has been a solid vehicle. Last winter it began to have a hard time starting, especially when it sat for a long time. It would turn over fine, but acted like no fuel was present. After a few seconds of turning over, or if I left the key in the "on" position, it would start fine. After a few months one day the fuel pump wouldn't turn on so I figured the fuel pump was the problem. I replaced the fuel pump myself w/ a cheapy from ebay.

 

The hard start problem has gotten worse since then. If I leave the car turned off for even 15 or 20 minutes, I have to let the fuel pump run before cranking the engine or it won't start right up. Sometimes I need to turn it to the on position twice, or let it crank over for a few seconds before it will start. If I turn the car off, it will start right up immediately with no problems.

 

I swapped the fuel filter, and it helped for 1 day. I thought I might be losing pressure at the fuel filter connections, so I tried wrapping the threads in teflon tape but it seems like it is worse now.

 

Any idea what is wrong? I have no idea how to trouble-shoot a fuel system. Any advice is appreciated.

 

Thanks.

[Leonidas Ureña Echeverr&#23]

Hello,

 

I have a 2001 suburban V8 5.3, engine hesitates a lot, dies on me on the road, starts back up but very weak. We just did a tune up and fuel filter change thinking that could be the issue but it actually got worse. I checked the fuel pressure and it is 20psi with the ignition on and 23 psi with the car running. I changed the fuel pressure regulator and the fuel pressure regulator vacuum hose (which has been discontinued by gm awful move), the problem still happens and the pressure is still the same.. There is no gas smell anywhere other than when the engine starts and it is hesitating, no black smoke. The only hose that I know it has a leak is the fuel intake hose from the gas cap to the gas tank... would that make the pressure drop that low? any ideas what could be causing the problem?

Edited April 18, 2015 by Leonidas Ureña Echeverrí a

[00Silverado4x4]

What about the fuel pump itself? If you're only get ~20ish PSI then I'd say your pump is toast.

[chevytahoe26]

Will fuel pressure regulator if bad allow the fuel pump to run continously on my 2002 tahoe 5.3

[problems]

got a 2009 sierra 5.3 been chasin this prob. to .. we r down to leaky injector anybody have issue with those 

[Calvin Williams]

How to start engine light comes on won't pass DEQ

[Adam Smith]

On 6/11/2007 at 11:38 PM, NealC said:

 

Is the "regulator" part of the fuel pump?

no the regulator is on the drivers side of the fuel rail

[CS8804]

I have a 03 GMC Sierra and have a slow drop in pressure as well. 55 psi to 20 in about 20 min. I too have to turn the key twice to get it to prime. Thought it was okay since it’s a theft deterrent but now I just want to fix it. I found that I had a leaky injector, so fixed that and hooked up gauge and it now more slowly drops psi but still drops. I replaced pump and did that splice connector thing and it still drops. Changed fuel filter and old one had a bunch of black stuff in it. I also changed the fpr. I think the fuel pump still might be the problem. I also get get a code of P0446z I read from another thread that the pressure sensor in the fuel pump was giving that code. The thread also stated the guy replaced pump again with a different one and all his problems were gone.  I tested the fuel pump directly and it gave me a really high pressure over 60 psi then slowly dropped but the gauge connection was leaking. I’m at wits end to figure this one out.