Bad lift pump?

[cumminss2000]

Today I was driving down the field road and went down a steep hill with the truck at an idol. I just got to the flat at the bottom and the truck started to stutter like it was running out of fuel. I gave it some throttle so it wouldn't die, it spat and sputtered some and when i let off the throttle it died. There is just over a eighth of a tank of fuel. I do have a draw straw in it but when i installed it i cut the bottom off little by little until it fit to try to prevent the 1/4 tank issue as much a possible. I've had the truck almost on E and haven't had any problems. I dumped about 2 1/2 gallons of fuel in, cracked injectors 1 and 3 and no fuel came out after cranking it. I loosened the fuel pressure sensor and no fuel there either. There is also none at the back of the fuel filter. I have a Raptor 150 that's about 10 months old. I pulled the fuel line from the tank to the Raptor off and only a dribble of fuel ran out. I can suck fuel out of the tank though. Shouldn't the Raptor be able to pump the fuel out if i can suck it out? And even if the lift pump isn't working won't the VP still pump fuel itself?

Sorry about the long post but I figured the more detailed i was the easier it would be to diagnose. Thanks for any help.

 

[LReiff]

Drain or replace the water separator.

 

[cumminss2000]

How could it be that if there isn't even any fuel getting to it from the lift pump?

 

[LReiff]

Is your raptor engine mounted or frame mounted?

 

[cumminss2000]

Its mounted on the frame.

 

[LReiff]

Well that should eliminate the possibility of a cracked supply line or air entering the supply line.

 

[cumminss2000]

Ya and I have the half inch rubber hose the whole way. Will the lift pump pull the air out of the line between it and the tank?

 

[littleboy]

I've seen a raptor air lock a time or so.....

 

[cumminss2000]

Ok. what do you gotta do to get it going again then?

 

[LReiff]

Open the outlet line...the one to the injection pump and leave the raptor run. Within a minute it should get prime. I suspect your fuel level sendor is faulty and the fuel tank was lower than you thought and you simply ran out of fuel.

Edit: remove the fitting on the raptor where fuel from the tank enters. Some units have a screen in the pump body, be sure it's not blocked with dirt.

 

[cumminss2000]

OK I'll try that. I was also thinking the sender might not be working. I did check the screen and it's clean. Thanks for the help.

 

[cumminss2000]

The pump was air locked. Thanks for the help.

 

[LReiff]

Funny stuff! I had one air lock today. I loosened the line to the filter and it instantly primed! Glad to hear you're going again!

 

[cumminss2000]

Really? What are the chances? Yup that's exactly what I did.

 

[LReiff]

I figured out why...or so I think. The fuel filter will easily pass air when new because the fibers are dry. Once the filter is saturated with fuel it can't pass air fast enough to allow the pump to lift fuel from the tank. Once you open the pressure line to the filter air can escape and the pump primes instantly.

 

[cumminss2000]

Ok ya I can see that. And next time I'll just unhook the quick attach connector from the back of the filter instead of screwin around with the hard to get at fitting on the pump.