Vortec 454. Starts fine when cold, starts fine when warm EXCEPT, after sitting for 10 minutes or more (and still warm). Then it has to crank for about 10 full seconds to fire, fires roughly, then clears out and runs fine. Symptomatic of leaking injectors or FP bleeding down.

Diagnostic process so far looks like this:
*Hooked up a FP gauge:50-60 lbs.
*Key off, pressure drops to zero in about 4 minutes.
*Crimp reurn hose... same
*Crimp Return and feed hoses...same
*Remove upper plenum, hard wire/jump FP relay and sure enough, I find two leaking injectors. (you can see them)
*replace the two injectors, reassemble, problem persists.

A week later. Engine starts to die while driving.
*hook up FP gauge; 20 PSI
*replace fuel pump and for yuk-yuks, FPR at the same time.
*truck runs again, but the warm-after-sitting-hard-start remains the same.

Right now, the FP still bleeds off (w/o the hoses crimped) in about 4 minutes. It has about 52 PSI at idle, and 60+ at WOT/no vacuum. It acts for all the world like leaking injectors, but if I kill it, immediatly relieve system pressure at the schreder valve (so presumably the injectors have little/nothing to leak), it's still a pig focker to start...after 10 minutes, but not right away.

Oh, one last thing, checked the CTS this morning at 100*F, 130*F, 160*F, 170*F, and 180*F. It check out fine, IMO. What is going on here??

 

Input please.

 

Theres only 3 places your can loose residule fuel pressure. You seem to have ruled out two of them. If you really want to be sure you can pull the entire rail and check for drips from the injecters but it sounds like youve narrowed it down to there already.

 

Again. Thanks.