problem fuel system

[cummins king]

okay i put half inch lines from tank to the mechanical pump and to the aeromotive pump with regulator and 2 check valves, seemed to be flowin good when i crancked the motor over, then i put the lines on the truck and it started first cranck (thing has been sitting for 1 and half months) i ran it for 5 minuts and i ran it throught the rpm's, then i turned the truck off and did a few things then i tryed to start it and it wouldnt start, so i made sure the was fuel going to the ic pump lots of fuel, wont start so i crack the injector lines then try again and it starts but it runs really ruf like motor is shaking like crasy, so im thinking that i ran it out of fuel, and i think its because it was sucking air, so i changed the system around and titened everything up, i havent started it yet but do yo think i missing anything....

i also put 25psi into the front of the stock ic pump, i dont think that would blow the seal out, theres no fuel it the oil that i can see

[PToombs]

Sounds like air to me! You should have started it when it was warm after swapping stuff. The only thing I can think of is air got in after you shut it off. If all is tight, you should be ok now.
Whether or not the seal will hold 25 psi depends on how old the seal is and how much more pressure it will get. Supposedly 15-16 psi is all you want to put to a VE. Just keep an eye on the oil level as you drive it, if it comes up, then

[cummins king]

thanks pt

okay i changed the set up so the lift pump is not in the system, so its direct from tank to the eletric pump, i do have a t in the line for the regulator return, do you think that the regulator return should go to the tank or is the t okay before the eletric pump, maby thats were the air is coming from but there should only be fuel,

any ways i cracked the injectors lines like 7 times and blead them, then the truck runs good for 20 second then the pressure drops from 25psi to 20psi and the the case pressure goes way down, and truck turns off and this happens every time, im thinking its the regulator return, what you guys think

[KTA]

Are you using the stock return on the injection pump? Does it still return to the tank like factory, and return the fuel injector bypasses too?

[cummins king]

return on injection pump is stock but on the old outlet side because the return barb broke, and the bypass return is t'ed into the suction line for the eletric pump

[KTA]

I don't follow your setup exactly, but your VE pump return and injector returns both need to return to the tank with no fuel pressure against them.

[cummins king]

okay

1/2 pick up
to a inline filter
to a T, to my eletric pump to a regulator (regulator bypass goes back to the T so theres no pressure against it theres acualy suction)

[ford69557ci]

im runnin a little different setup but my return off of the bypass regulator runs back to the tank and i left the factory return system alone. I have had no problems with it setup that way.

[cummins king]

you know i couldnt sleep all night because i was think of how dum i was to put the regulator return into the T for the suction of the eletric pump, of course its ot to go back to the tank

[KTA]

I was talking about the return from the injection pump, not the return from your regulator.

[cummins king]

i know the ic pump return is stock, but the regulator return is were the problem is, why do you think there may be a problem with the ip return

[KTA]

Because a blocked return on a diesel will let it start and run awhile, then it dies out, let it sit awhile, and it will restart, then do the same thing. It was just a suspicion since I know you were talking about fuel flow and modding the return in another post somewhere.

[cummins king]

okay im am positivaly a few time stumped

okay this is my system as of tonight

1/2 inch pickup
to my aeromotive fuel filter,
1/2 inch line from my aeromotive fuel filter to my aeromotive fuel pump
then to my aeromotive regulator, then to a guage
the to a check valve then 1/2 inch to my ip ,

the bypass part on my regulator is 1/2 inch line back to the tank

the return for injectors and ip is stock

the truck will idle it will go through all the rpm's and then idle, it runs perfict,

But....... then i turn it off and and try to restart the truck wont start and waiting wont help,

before i started this morrning i checked the oil, its 1/2 way between the safe and add mark, and when i finished tonight its in the exact same spot

Pease Help

[ford69557ci]

your fuel filter needs to be between your lift pump and ip aeromotive pumps dont like to draw through a filter and you want it after the lift pump to keep and debri the pump might make from gettin into the ip

[cummins king]

i dont have the lift pump any more seems to be sucking find with the filter before it, and its flowing fine