Alright, I just replaced the lift pump, thinking it was shot. No such luck. I tried priming it, must have pressed the primer at least 200 times, nothing comes out of the filter canister. So I threw some duct tape over the filler neck and shot some compressed air in with the bleeder on the fuel filter canister open... Still nothing (and yes, its getting at least 5psi which should be enough).

Before anyone asks, I do have fuel, little over 1/4 tank right now.

Why am I not getting fuel? Its not leaking anywhere, and its been sitting in my shop for a week now, which is at a pretty constant 55*, so I know its not gelling.

HELP!!!

 

in tank strainer plugged ? any way to add air back to the tank through the feed line, to free it up ? repeated light shots should dislodge crud, sure it will crud up again but later, and you are back on the road for now.

 

Is that really all there is? I'm thinking just pulling the feed line to the strainer bowl, and blowing air in there. But from the sounds of it I need to drop the tank and clean it out.

I didn't realize there's an in tank strainer.

 

Lift pump should be in your fuel tank. Is the pump running when the key is turned on? I think it only runs for 15 sec. at first and again after motor is running.

 

No...this is a 12V, there is no in tank pump...

 

I had this problem with my holley blue pump when i first installed it. So i took it off and primed with pump with two buckets of fuel. Suck from one and push into the other. After i did that i re-installed my pump on the truck and i had fuel almost instantly.

 

Use a small container of fuel , run a hose from it to lift , meaning disconnect the fuel from tank , try priming then & see if truck runs , to make sure everything is working .
Then use a spare fuel tank cap , put a valve stem from air wheel into the spare cap , make sure this is air tight , then use that to put about 3 lbs air pressure in tank , then with a flash lite check every inch of fuel line & hose for fuel leaks , normally from tank to LP is a vacuum , so they suck air [ can not see ] .
While the fuel is disconnected at LP is a good time to see if you can blow clean any sock , I've had some 24v fuel tanks off and saw no sock , but that does not mean that all trucks have no sock .

 

This is new one, like to hear what it turns out to be.
Thing that is odd it that when you pressurize the tank fuel flows though both the feed and return lines. Would be very unusual for both to be plugged.

 

I would bet that there is a chafed or rusted through hole in the suction line and all you're doing is pumping air. Check out all the lines carefully.

 

I don't know what to do anymore... I'm about ready to shoot the &^%$#% thing. Its been nothing but a pain for me, I've owned it for 6 months, and been able to actually drive it for less than 3.

Bill, How does fuel flow through both lines? The OFV should stop air from going past it. I'm going to try blowing air directly into the feed line, and see if that free's something up, otherwise I might just pull a chunk of the feed line out and put in the Holley Black pump I have sitting on the floor of my shop. If that doesn't get fuel to the lift pump I have a big problem.

 

have you checked your pre filter screen in the fuel heater? Its right next to the lift pump. if i remember right fuel goes into that before it hits the lp. I suppose its possible if it was cold that it plugged up with parrafin, or something else.

 

Pressurizing the tank will air lock the fuel system and bind the P7100 injection pump with air. Pull the return line after the check valve and then put about three pounds in the tank. The fuel should run out the return line if everything is good.

However, your problem sounds like the pick-up tube is compromised in the tank. That is a very common failure, they are synthetic rubber and crack just about the two thirds level and then the fuel systems fail when the tank drops too low and the crack pulls air. That in-tank hose should be replaced once every few years to be sure it is good.

 

Well I don't think I bound the pump with air, I had the bleed bolt pulled out of the fuel filter canister.

I really need a second set of hands so I can find out if air is coming out of that bleed hole when I pressurize the tank.

Its not the prescreen, I pulled that first thing and while it did have a few shavings of aluminum, it certainly wasn't plugged.

Thanks for the help RCW, do I have to drop the tank to get to this pick up hose? Or is there an easier way?

 

Take a deep breath , doing anything while your upset is most likely going to make you fail .
You need to look at this in a systematic way , as an example , your taking a bolt out while putting air in tank , if you do that , and there was an air leak between tank & lift pump [ normally vacuum ] , you not going to see fuel coming out of a line or hose [ you need to keep the other end plugged to get fuel to come out a leaking hose / line .
You said you found metal chips in the prescreen/heater , that is not good , The lift pump uses check valves , if some piece of anything gets caught in either check valve , the LP will not pump .
So 1st disconnect the fuel to LP from tank , put on an other hose into a small container of fuel near the eng. , try to start , what to see if it looks like there is fuel getting sucked out of your small container [ maybe air bubbles ] not a good sign .
If the eng starts , then it is going to be the hoses , lines or tank .
This is when you want to use about 3 lbs of air pressure to look for leaks .
You have the wrong idea about the OFV , it is what regulates the fuel pressure from the LP , by restricting the return to the tank .
Any fuel injected [ gas or diesel ] has a loop { 2 lines , out & in } from tank to eng , then return to tank .

 

I first thought you had a case of algee, but you say some fuel flows.
I had one a few years ago that was full of algee and it had a sock in tank. ( this was an old bread truck.) Cleaned it up and treated it too, it was good to go.
BTW, the primer valve must be off of the cam lobe!! Turn the crank 1 turn and keep trying.