1990 474 cid inline 6 fuel system

[Gbro]

I have always struggled to reprime after filter c/o and had an air bound secondary(injector pump) that only cleared when return check was loosed.
This is in a 1991 F-800 with the 1990 holdover engin so my shop manual doesn't cover my engine (go figure).
I would very much appreciate if anyone could tell me the Lift-pump pressure spec.
This system has a rubber seated check on the return to tank bypass mounted on the P-Pump with a cracking pressure stamped on it 1.8 bar (26 psi).
I do not have any return flow from this check(regulator?) and didn't with an electric pump either.

I am being counseled to mount an electric pump in place of the Lift-pump and if I do, what is normally done with the old lift-pump??

Thanks for bearing with me.

Greg

[Gbro]

I am up and running.
I took the lift pump in to a service center and had it rebuilt. Everything looked good, but check seats were lapped and new hand primer.
Out the door cost on rebuild was $45.00.
I installed and primed the system. I left the return line disconnected until I primed and after purging filters, 3 pumps and I overcame the regulator(check w/26 psi cracking pressure).
The engine fired off after about 5-6 seconds cranking at full throttle.
This is the 1st time ever this truck started without injector line bleeding.
I am one happy bone head mechanic wannabee!

[nevrenufhp]

Good to hear it all worked out, and for that cheap! You're not a wannabe anymore.