Been having a hard start quite frequently as of the last 3 weeks. First I thought it was a dying VP, but I noticed something today. My FASS doesn't always do the initial cycle when you turn the key on. Bump the starter, and it goes, but it starts about 2 seconds later than it normally would when doing so. A month and a half ago, I had my FASS did not run at all, drove about 300 feet by the time I realized it (truck was jerking around, not smooth at all). Killed it, turned the key on and the pump ran fine. I got P0628 'Transfer pump circuit out of range' code. Never had an issue of the FASS shutting down while driving, and never noticed the pump not running on startup until today, although I'm betting thats whats causing my hard starts. Fuel pressure is always good otherwise, 15+.

So the question is, what is a likely culprit causing this? Would a dirty connection cause a delayed start? If the ECM is setting a code, would that be a fault inside the ECM itself, or would one be set if it didn't make a circuit with the lift pump? I'll go clean up the connectors tomorrow before I head off to work.

 

I am not sure what kind of circuitry you get with a FASS, maybe it has a relay that is not working very well? Clearly this is something related to what you have plugged into your former LP connector.
-P