07 Suburban LTZ 5.3 flex, 108K

Recent work: Plugs and wire change, clean throttle body, new air filter, replace tranny filter, lube in all transfer cases replaced, including 4wd.

So I hopped in the truck yesterday, turned the key and released to let the auto complete finish. I didn't start. I turned the key and it started right away. Turned the vehicle off and it started right away. Waited a minute and it started near the end of the auto complete cycle.

The vehicle runs well, no hesitation, but is a bit doggy (I think that's mostly due to poor shift points). I don't smell any excess gas while it's running, and a visual inspection under the hood reveals nothing. The problem started after the service where the plugs/wires/tranny filter/transfer case lube service was done. I did the throttle body and air filter about a week before that service. Pushed all the wires in, no misfiring can be heard.

I'm having a hard time believing it's the fuel pump because it seems to be running fine. But that doesn't mean it isn't the fuel pump. It just seems like there's no gas the first go-around and on the 2nd there's gas there for starting. Could I be loosing my "prime" somehow?

What's the collective brain trust out there think??

 

Ok, vehicle is diagnosed as having a faulty check valve in the fuel pump. It's allowing the pressure in the line to bleed off after the vehicle is shut down, causing the long start cycle. Anyone know of a solution short of replacing the pump?