Brand new to the forum, thanks to the new-to-me '05 Suburban we just got. Just in the last week, it has gotten to where almost every time we start it, it cranks for 3-5 seconds before starting. Priming with the key on a few times helps. I checked fuel pressure at the rail this AM and here are the readings:

1: after sitting all night = 0 PSI
2: Key On Engine Off = 61 PSI
3: Running = 61 PSI
4: Leak down test = 0 PSI within 3 seconds of shutting off the engine.

So, obviously it's losing pressure almost immediately. I assume from what I've read this means I'll be dropping the tank to replace the pump. However, the Haynes manual says for the flex fuel engines, KOEO should be 48 - 54 PSI and running should be 3-10 PSI lower than KOEO. While I have the tank down, do I go ahead and replace the fuel pressure regulator as well?

Is there anything else I might be overlooking (I will obviously check the hoses from the tank to the engine before dropping it, but it runs perfect once it's started so I doubt that will be an issue.

Thanks,
-Chris

 

The regulator is not on the tank it is on the fuel rail under the hood. Replace the pump very common problem.

 

The regulator should be at the pump, since it's a 2005 with the "returnless" fuel system. I guess my question is should I just suck it up and replace both while the tank is out?

Thanks,
-Chris