Rough Idle & Lack of power.

[Evan Williams]

I have a 87 6.9 4 speed 4x4 with the 085 ats kit. Used as a work/farm truck.

While driving to has a surge in power or no power. It idles ok but then it starts to idle real rough then back to normal then back to rough.

Acts like it’s not getting enough fuel. I can hold my foot steady and it will speed up and slow down on its own. Like it’s starving for fuel. Sometimes It will suddenly go balls to the wall on its own for a second or so. It has started to die every once in a while (when slowing down) Some days it don’t to it as bad as others. Already put a new fuel filter and plan on getting new injectors or putting new o rings on these.

 

[IDIBRONCO]

It sounds like you're sucking air on your feed side of the fuel system. That would be before the lift pump.

 

[DaveBen]

Welcome to Oil Burners Evan Williams! Glad you joined up.

 

[franklin2]

It sounds like you're sucking air on your feed side of the fuel system. That would be before the lift pump.

I agree. We had a f350 dump truck with the 7.3 that would surge like that. Turned out to be sucking air, the fuel line leading from the tank up to the fuel pump had a leak. I had to replace the whole line from the tank all the way to the front. I used new universal steel line from the autoparts store. Problem went away after that.

 

[IDIBRONCO]

Mine was the infamous rubber line between the steel line and the lift pump.

 

[Laine D]

Mine was the infamous rubber line between the steel line and the lift pump.

Same. Imagine the person who owned the truck before you using 3 pieces of fuel line connected by plastic barbs in that spot.... I had a little air intrusion. Wish I took a picture lol