my truck is actually doing the same thing as yours right now, I'm leaning towards the fuel pump, funny thing is, its only a year old fuel pump, but, it doesn't hold pressure any more after shut off, so I know the check valve is shot already!! also, when you check your fuel pressure, put the gauge on before you start the truck on that day, then take it down the road were it usually acts up, this will be the critical point to be watching your gauge and see if the pressure drops!! I do believe with a bad check valve, there could be an air pocket in the fuel rail which shows up at about the same time every morning after start up...

 

Gonna check it again when i get home make sure i didnt have a leak in the pressure guage

 

Kinda hard to replicate the conditions cause mine only seems to do it under load, not just idling at start up.

 

Took the 1st tester back I think it had been abused. Using the second one pressure seems to hold after turning engine off. Wouldn't it still show pressure even if it was air?

 

44dakota let me know how urs works out. My pump holds pressure at correct range so i got to look another problem.

 

Have had some people guess it could be the throttle body needs cleaning. I have already cleaned it but why woukd that cause it?