No start on first try

[dennyandcarrie]

I have a 2005 Suburban 4x4 Z71 5.3liter Flex. If the vehicle sets for a few hours i have to cycle the key two times to get it to start. It will always start on the second try. I think there is some kind of valve on the fuel pump that helps to hold the fuel pressure after you turn off the vehicle? If that is what is bad is there some kind of one way valve I can put on the fuel line outside of the tank so that it will hold the pressure when the engine is off or do I have to replace the fuel pump to fix it?

This may already be in another thread but I could not find it. If it is just send me the link and I will study up on it.

Thanks

 

[Mooseman]

I would suspect the fuel pressure regulator instead because it maintains pressure to the fuel rails. It could be the pump itself if it doesn't supply enough pressure fast enough. Only way to properly diagnose is checking the fuel pressure with a gauge.

I'm not sure there is such a valve in the fuel pump assembly.

 

[dennyandcarrie]

Ok I feel really stupid. I cannot find the fuel pressure regulator. Everything I see online shows it on the drivers side fuel rail with a vacuum line attached. Mine does not have anything like that at all. Is this particular one in the fuel tank on the pump or am I missing something.

 

[Mooseman]

Just remembered that 2005 went to a returnless system. RockAuto does list a FPR but 2006 does not. Sometimes parts are listed for transition years or it's simply an error for 2005 only.

However, looking up the fuel pumps for 2005/06, it does say that the FPR is in the fuel pump module. I would test the pressure first and make sure there is no leak anywhere, including at the injectors.

How many miles on the truck?

 

[dennyandcarrie]

There is 146,000 miles on it. I suspect it is about time for a pump. I have seen no fuel leaks around anywhere and do not smell gas. I will have to get a fuel pressure tester and see what is going on.