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Hey guys brand new to this forum, I’m trying to figure this thing out. My work has a 96 F800 with the 5.9 in it and an Allison backing it. I don’t know how much different this 5.9 is from any other. I’ve searched and searched and cannot find much info about this thing. So basically I pulled the full tank on this thing because it was leaking, had it patched and sealed. Replaced the tank and filled it up, primed the s*** out of the system to the best of my ability and couldn’t get it started. I’ve tried pressurizing the system, bleeding the system, using a hint of ether, and just about everything else all of the forums have said. If I fill up the fuel filter and use the priming while having someone crank we can get it going and it’ll run off the fuel in the filter for about 20 or 30 seconds and then stall. I’ve check the tank to make sure the pick up tube isn’t clogged, I’ve used and electric fuel pump to the Ip and it doesn’t really want to start there but I could probably get it to go. Anyway my main question is does this sound like a bad lift pump? The truck ran fine before I pulled the tank.
 

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When your bleeding the system at the filters bleeder are you seeing many air bubbles, also with the bleeder open crank the engine over and watch to see how much fuel comes out. Should be about 15 psi on a good LP at idle.
 

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When your bleeding the system at the filters bleeder are you seeing many air bubbles, also with the bleeder open crank the engine over and watch to see how much fuel comes out. Should be about 15 psi on a good LP at idle.
Well when I manually fill up the fuel filter and bleed it I can get a steady stream of fuel. Yeah I doubt I’m getting anywhere near 15 psi, but I think I’ll try that next. Thank you
 

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You must do more searches and download and consult the factory service manual. When you've read every post on this forum and have read the entire service manual come back.

Ok, just kidding.

I had a lift pump die on me after I parked in my driveway. Fine one day and dead the next. Also, sucking air from somewhere is possible too. The suction lines won't show fuel leaks always.
 

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You must do more searches and download and consult the factory service manual. When you've read every post on this forum and have read the entire service manual come back.

Ok, just kidding.

I had a lift pump die on me after I parked in my driveway. Fine one day and dead the next. Also, sucking air from somewhere is possible too. The suction lines won't show fuel leaks always.
Almost had me haha

Well the thing is the truck was running great before I pulled the tank, started right up every time no issue. So that’s why I’m leaning more towards the lift pump and not the lines
 

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I’d run the fuel line over into a clean bucket of diesel and try it. It sounds like you might have a fuel line pinched or restricted. Typically when I have something fail or malfunction I go to the last thing that I worked on. You saying it ran fine before dropping the tank would lead me to believe the problem lies somewhere between it and the lift pump
 

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Stupid question but is there any way you could have the inlet and return lines to the tank swapped? I’ve seen that on a big truck fuel tank once.
 

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I’d run the fuel line over into a clean bucket of diesel and try it. It sounds like you might have a fuel line pinched or restricted. Typically when I have something fail or malfunction I go to the last thing that I worked on. You saying it ran fine before dropping the tank would lead me to believe the problem lies somewhere between it and the lift pump
Try this it will rule out a possible problem with the tank or lines to it.
 
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