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I NEED HELP TRUCK RUNS OUT OF FUEL AND I SHUT KEY OFF AND LET LIFT PUMP FILL FILTER AND IT WILL RUN FINE FOR A MIN OR SO THEN DO THE SAME THING REPLACED FILTER AND HAS A AIR DOG RAFTER LIFT PUMP THAT IS NOT AS LOUD AS I REMEMBER IT BEING. I'M STUCK AT WALMART PARKING LOT TILL I FIGURE OUT DON'T HAVE MUCH MONEY TO TRY THINGS LIKE NEW LIFT PUMP IF THAT'S NOT IT I PUT THAT ONE ON A LITTLE OVER A YEAR AGO. ANY HELP IS GREATLY APPRECIATED 

THANKS

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Just to be sure I understand.....  Your truck will start but only run for a minute or so?  You can hear the fuel pump pumping but it doesnt sound the same?

 

How much fuel is in the tank?

Do you have any fuel pressure gauges to help understand if you're getting any or the correct fuel pressure?

 

I know you're frustrated and probably in panic mode but be precise in whats going on and explain in detail so we can understand best to help.

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Just to clarify.  The truck ran out of fuel?  You have recently changed the filter?  After you prime the fuel system, you can hear the lift pump run, but it is running louder.  After it primes it will only run for a minute? 

 

Do you have a fuel pressure gauge?  Is it throwing any codes?  Have you tried priming it and loosening an injector line?  How much fuel is in the tank?  You need to make sure that the LP is indeed running and if you can loosen a line that goes to the IP you can verify that it is moving fuel.

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Denver

21 minutes ago, Hawkez said:

Just to clarify.  The truck ran out of fuel?  You have recently changed the filter?  After you prime the fuel system, you can hear the lift pump run, but it is running louder.  After it primes it will only run for a minute? 

 

Do you have a fuel pressure gauge?  Is it throwing any codes?  Have you tried priming it and loosening an injector line?  How much fuel is in the tank?  You need to make sure that the LP is indeed running and if you can loosen a line that goes to the IP you can verify that it is moving fuel.

No it never ran out just started missing like then I shut off knowing I didn't change filter for awhile I changed it and it fills up and runs for a min or so and wants to die but if I turn key on and off it does it all over again. No Gauge no codes plenty of fuel  

Edited by Gusdodge
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So does it die or is it stuttering?  After I start my truck after priming it will stutter for a second or two and then smooth out.  Look for signs of lose fuel connections.  Also, have you done any mods to the truck, is there a programmer on it?  What about fuel pressure?

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A few things could have happened.....

 

Your fuel pump could have quit and you're not getting the correct fuel pressure or volume in order to get the truck running.

 

You could have ran out, or be running out, of fuel if the fuel gauge is anywhere less than 1/3 tank.  Fuel gauges can be way off depending.

 

Either way, you have a whole lot of air in the system now and you're going to have to crack loose a few injector lines in order to purge that entrapped air out so it will start.

 

Any thing else would typically generate a code.

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When the lift pump went on me little over year ago it would still run fine off the injector pump but now with this raptor lift pump is there a reason it would block the fuel not letting injector pump pick up slack I know it's hard on it but just wondering if lift pump is weak or what the issue is 

It runs perfect for about a min a little less if i Rev it up then will sputter and want to dye unless I feather pedal. probly will stay running if i just let it idle seems like a fuel pump but not positive cause what it did last time ran fine till i went to change fuel filter then it would not fill filter bowl back up but it will fill the bowl up

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My first lift pump failure and the truck died and would not start. My second lift pump failure and the truck kept running. I have read where a lift pump failure can take the VP with it. Many combos of what can happen. With 2 lift pump failures on one VP might be pushing it. I would expect to see a DTC set if it was the pump. How are you checking for codes?  Still could be air in the system or fuel starvation. Does sound like it.

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5 hours ago, Gusdodge said:

When the lift pump went on me little over year ago it would still run fine off the injector pump but now with this raptor lift pump is there a reason it would block the fuel not letting injector pump pick up slack I know it's hard on it but just wondering if lift pump is weak or what the issue is 

It runs perfect for about a min a little less if i Rev it up then will sputter and want to dye unless I feather pedal. probly will stay running if i just let it idle seems like a fuel pump but not positive cause what it did last time ran fine till i went to change fuel filter then it would not fill filter bowl back up but it will fill the bowl up

 

Letting the VP pull its own fuel supply is very damaging.  Yes, the stock lift pump would allow fuel to pass when the lift pump was not running which would mean the engine "could" continue to run.  But the Raptor doesnt do that and will shut off all fuel supply when the pump isnt pumping.  You need a fuel pressure gauge to know if you're getting any pressure from the pump.

Edited by KATOOM
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When I first bought my truck I wouldn't even drive it till I got a fuel pressure gauge. Just too much risk/ expense to go without.

 

When you first bump the starter, truck not running, the lift pump should be running for about 25 seconds after bumped. This is an advantage cause when not running it quiet enough to hear if lift pump is working.

 

Air in lines and also not fully priming can cause a short rough engine run and then die, but, you say it runs for a full minute? 

 

Stay away from the dealers but a couple things possible:

Air leaking into lines

Bad overflow valve on the vp44

Tank vent causing vacuum in the tank from clogged anti roll over valve on tank top. Just remove the cap while running.  Or remove fuel cap slowly after running to see if you hear tank vacuum. This problem is rare but happens.

Old intank lift pump left inside the tank.

Quick connect fuel lines leaking air.

 

You got to get this truck home and talk with Eric at Vulcan performance. He's sharp and his prices are spot on good.

 

 

 

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Ok thanks, is it common for overflow valve to go bad.

That's good to know that the raptor will not let fuel flow without running so im pretty sure it is either the overflow valve or lift pump. I can barely hear the lift pump run and I used to be able to hear it easily thaught it was kind of loud but not anymore 

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Troubleshooting this really isn't that complicated, but as has been mentioned you need to know what your fuel pressure is coming from the LP.  Since you haven't mentioned it, I assume that  you do not have a FP gauge in your truck.  You may be able to rent one at an auto part store.  There should be a schrader valve on the IP where the fuel line come in from the LP.  Having a FP gauge in the cab is essential, but this would help you figure out what is going on.

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DONT TOUCH THE OVERFLOW VALVE.....!  The odds of those simplistic check ball and spring valves going bad is highly remote and far too often blamed.  There's nothing to go bad.  And that said, if it does stick either open or closed, the truck will still run.  It will just cause hot fuel conditions or hard starting.  Either way, its pointless to try and diagnosis the overflow valve as the fuel flow through the VP is not simply in and out.  The fuel passes through the entire housing before exiting.  Move on to the other more plausible culprits. :thumbup2:

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20 hours ago, Gusdodge said:

Ok thanks, is it common for overflow valve to go bad.

 

10 hours ago, KATOOM said:

The odds of those simplistic check ball and spring valves going bad is highly remote and far too often blamed.  There's nothing to go bad.

 

This comes from the 12V engine that was common for the overflow valve to become damaged and create issues. In the 24V or VP44 fuel system they are super rare to fail ever.

 

What is you fuel pressure like? If the lift pump is no running properly or creating enough pressure then it can create these issues.

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Katoom, what do I know anyway . My overflow always works when drinking beer:nadkick:

I think Gus needs to revamp his entire fuel system. Without a F/P gauge  I wonder if he's still running banjo bolts, no 3/8ths or 1/2'' inch lines, clogged screens in the tank. no prefilter before the lift pump, could be a lot of things that need revamping before the possibility of ruining another VP if that's what is found to be wrong. All I know is Dodge engineers screwed the fuel system in these trucks.

And their solution at the dealers is to place an inside the tank fuel pump that makes it worse.

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