fass issues

B

battle axe

New member
i put a fass on my 91.5 cummins. its running out of a fuel cell in the bed. the fass is mounted in the bed aswell. I have all the lines hooked up correct and with hose clamps. The truck will start and run for like 15-20 seconds and then die. no throttle responce after 10 or so seconds.
 
Hmm...

Any white smoke in this time?


A VE pump can suck enough fuel on itself to keep itself running, provided that the lines are clean. What's your fuel pressure like from that FASS while the truck stalls?

Any chance that you wired it to the crank signal instead of the run signal, and so it primes the system when you crank, then stops, and there's only 15-20 seconds worth of fuel in the lines and injection pump at that point?

If the FASS is operating correctly, I would next look at the shut-off solenoid and make sure it's getting a clean voltage and is wired correctly.
 
shut off silonoid hasnt been hooked up for a year. Fass will pressure up like a normal one.i have it straight to the battery right know to make sure everything works. just got a fuel pressure gauge.
 
I'm thinkin the triger or key on key off is not wired correctly I had that problem with my AD so to fix that I went and gotr power from the shut off sylinoid(cause I got a cable)and that fixed mine hope that helps good luck
 
As long as pressure supplied to the injection pump comes up and stays up, and the engine stalls anyways, I guess we can call the lift pump good.

I would check the suction side of the system thoroughly to make sure that suction isn't sucking anything shut or opening up any air leaks.

You can try gravity feeding the VE to see if the problem stops. If not, it strongly implicates the injection pump or something bizarre.

I assume that when you unplugged the shut-off solenoid you took the plunger out.

Have you tried playing with throttle position to see if you can keep it from stalling?
 
i have the fass figured out now. But i have no power. 10psi @ 850* with my foot through the floor. The truck ran fine with the auto, i put a nv4500 in and never touched the pump for the 8 months that it sat. I put my hand over the turbo and watched all the intercooler boots suck flat, so i dont think it has a boost leak. Why doesnt my pile make power? It has a maxed pump no afc and a denny t pin. So i should have some black smoke but i dont. in nuetral at about 3800 rpm in will build 7psi and 10psi on the road.
 
Maybe the fuel air separator isn't removing enough air from the system. The only thing I can think of, maybe is with the VE return plugged/no longer functioning, the injection pump is not self venting or removing air by sending it back to the tank. Just a guess. I'm not 100% sure how the system works.
 
Hook up your VE return yet? Get it figured out?

I was thumbing through one of my Cummins books and under the troubleshooting section or 'Low Power', one of the checks was check for a restriction in the injection pump fuel drain return. That was the jist of it. Said overheating of the fuel is a result.
 
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