When i get in this thing and crank it over, it cranks til it quits and then you can crank it again and it starts every time. It has no codes. i have narrowed down to cat problem or evap canister. any other ideas? 2008 5.3 L 4x4 single cab. thanks for any help!

 

Welcome to the forum. I don't see a connection to "cat problem or evap canister" but I guess anything is possible. Maybe it's covered by the powertrain warranty?

 

Sounds like a fuel pressure problem. It could be the fuel pressure regulator or the check valve in the fuel pump. I had the same problem and it turned out to be the check valve. I changed the fuel pressure regulator and it did not solve the problem. I put an inline check valve before the fuel filter and solved the problem.

 

thanks for the info.i will try the check valve

 

1. I 2nd fuel pump check valve problem.

2. if it is an EVAP problem then the purge solenoid is stuck in the open position allowing constant flow of fuel vapor to the engine during starting, simulating a flood condition.

but I think your fuel pump is doo doo.