FireDodge

Was driving home last night and the truck was having problems between 40-60mph. I had no more power above 60mph and could press the pedal all the way to the floor and not get above 60. Thought it could have been a fuel filter issue so i replaced it this morning. My girlfriend took my truck and she was still having the same issue. She could get it to 70mph but it will struggle to get there. She was at a stop light and the truck cut off on her. She was able to get it back running and get it home. Any thoughts on this. I feel like it is a fuel issue but dont know where to start now that i have replaced the filter. Any help would be great. 2006 2500 5.9l.

Adaminak

Any codes? Can you hear the fuel pump run when you bump the key to start position?

papaduck

Sounds like the lift pump is failing.

Adaminak

I agree, but it's pretty rare for the in-tank pumps to fail...

cdennyb

bite the bullet, it's your lift pump. 99% sure.
Any chance you can put fuel pressure gauge in the line between your filter and the injection pump? That'll tell the tale.

FireDodge

Any more info on the lift pump? I put some fresh fuel in it to get it home on friday then went out of town for the weekend. Truck had to sit over the weekend. Got home yesterday and started it up and let it idle for about 45 mins just to be sure that it still runs. Started up ok and idled normal for the entire time. If it was the lift pump would idle be affected? if i put a guage in the line where would be the best place and what kind of pressures am i looking for? Thanks in advance for your help.

papaduck

An engine will demand more fuel as the throttle is increased. The pump could be giving you fuel for a lower demand and when you increase the demand beyond what the pump can supply the power will fall off. If the pump completly fails then the engine will not run unless the CP-3 can pull the fuel through the failed lift pump.

At idle the pump should be holding around 8 to 10 psi, at WOT(wide open throttle) the pressure should only drop by 2 or 3 psi. If the pump is holding at least 2 or 3 psi at WOT then the truck should run OK. A pressure guage is the best way to test the pump.

There is another test that is done by volume and time but I do not remember the numbers. If you catch the fuel from the filter drain and cycle the pump by bumping the starter (do not start) and leave the switch on, the pump should run for about 30 seconds, you should get a quart or more fuel.

It is possible that the there is a restriction in the supply line or tank that could be reducing the fuel flow. But with the pump in the tank it makes it harder to check.

FireDodge

ok, dont know if anyone is reading anymore into this thread, but i replaced the fuel filter twice and put in a fresh batch of fuel and ran it for a trip to the beach and back. Have had no more issues with it. Think that i had some bad fuel. seem to have full power back now

Zeus1987

Good to hear ! did you have a check engine light while it had low power ?

Adaminak

Glad to hear you got it worked out, and thanks for the update.

rockcrawler304

Good news!!

FireDodge

Zeus1987, I didnt get any check engine lights when I lost my power. Nothing was out of the ordinary with components or warnings, just flat out no power above 40mph. I didnt check codes but probably will this weekend just to make sure there is nothing underlying that I may have missed. Guess moral of the story is to stay a little more on top of my preventative maintanance!

2hipsi

Yeh, Sounds like a bad batch of fuel that was plugging the filters up. It could still however be a weak lift pump that is working intermittently. It wouldn't hurt to check the fuel pressure and make sure its where it should be. And keep a spare filter on hand cause it may take another tank or two to get it out of the system totally.