Poor to no acceleration Problem?

[chestatee]

1994 6.5td -
A week ago when driving I had less than 1/4 tank of fuel and it started de-accelerating to about 30 mph and would do nothing beyond that speed until I had to pull over because it simple would not move. Someone brought me 10 gallons of fuel and then I filled it up.
It's been running fine until today, the water in fuel light came on then off and then stayed on and the truck started running like before even though it has 3/4 of a tank of fuel, I drained fuel manger to clear any water. The truck will start and go 20 feet and then act like its starving for fuel, it makes no difference if you push the pedal to the floor it sits there. Wait 10 minutes it will crank and go 20 ft etc.
Thanks for your time and thoughts

 

[marvgarr]

Any codes? Change the fuel filter and make sure no water in the fuel. Remember water is heavier the diesel so it will pump water from the tank first.

 

[ak diesel driver]

check to see if your LP is working

 

[Burning oil]

Whats your fuel psi?

 

[Will L.]

Did you take the chain off the back bumper that's hooked to the tree?
Actually I'm thinking something is plugging in the tank sock. So again back to a fuel pressure gauge. One with a vacuum reading on it incase it is restricted...

 

[WarWagon]

I would deal with the water first. STOP RUNNING THE ENGINE NOW!!! You must get all the water out of the tank before you continue playing with getting the engine running. Water will kill the IP and injectors quickly. (The word instant comes to mind with core value ruining rust quickly after it fails.) If you are lucky the fuel filter has restricted and stopped the water preventing damage. Running a full vacuum on the plugged fuel filter will eventually force water through it.

You need to drop the tank and get all the water out of it. The fuel pickup sits above the bottom of the tank so if the FFM got water their is quite a bit in the tank. The fuel sock is trying to stop water as well.

The new ULSD fuel will hold more water than in the past. So the fuel is extremely wet and you should consider throwing it away as waste oil. $100 in fuel vs. $1200 IP, no core value, and $500 injectors is a no brainier. Further you should run some fuel soluble biocide just to keep the critters in check from that much water.

I would throw away the tank sock and run an after market water separator before the lift pump. Those work $1000 times better than the factory filter. $ because of the IP it saves from water... Use a heater assembly prefilter if you ever have colder weather to deal with.