Fuel starvation after filter change (1 Viewer)

[jrdobbs03]

Guys,

Knocking out things on my build and just did a filter change. Just runs fine on the highway and crawling, but if I really get on the throttle then let off completely it acts like it’s starved of fuel.

I filled the filter to the top on the swap out, but maybe I got some air in the system.

Any advice?

 

[BreckenridgeCruiser]

Did you bleed the fuel system? Does your fuel filter have the bleed screw or priming plunger? Not sure if that's the issue, but I'd check that first.

 

[jrdobbs03]

Yeah love to do that. Done it plenty on my other diesel trucks. But I can figure out where to bleed this one from.

 

[BreckenridgeCruiser]

I assume this is the HDJ8x?

There should be a black plunger on top of the fuel filter. IIRC these don't have a bleed outlet, you just pump until it gets firm and that should mean the air is out.

 

[CycloSteve]

There should be a black plunger on top of the fuel filter. IIRC these don't have a bleed outlet, you just pump until it gets firm and that should mean the air is out.

This is what I do with mine. Never had an issue after servicing the filter (every other oil change). The other thing I would check is to be sure that there are no leaks where air can be entering the fuel system. Did you use an OEM filter, or aftermarket?

 

[roscoFJ73]

If it was air it would be running rough because the fuel has bubbles in it. If it is running smooth, but underpowered, the problem is elsewhere.

 

[roscoFJ73]

I assume this is the HDJ8x?

There should be a black plunger on top of the fuel filter. IIRC these don't have a bleed outlet, you just pump until it gets firm and that should mean the air is out.

Air must go somewhere. I think it must get pushed into the fuel return when it starts as it the highest point in the fuel feed. But between the pump and injectors you are supposed to loosen the injector lines off.

 

[BreckenridgeCruiser]

It could vent from the pump mechanism... I was just saying there isn't a bleed screw.

It could definitely push into the return line, but my best guess is it just vents at the pump or else you could just start pumping fuel through the system?

@roscoFJ73 this is just my best guess as I don't have this truck in front of me, but have a similar fuel filter on my HZ and it just pumps until firm and then that will bleed air from the filter back. If it still won't fire, then you definitely need to crack the injectors to bleed air through the pump and injection lines.

 

[Squash]

If it starts and runs air will bleed out with now need to crack injectors.
You are most likely sucking air with fuel from wherever and whatever you just took apart.
Vaccum leakage does not leave evidence because air is being sucked in.
All connections need to be tight and hoses in good shape. You can also try the clear hose trick between your IP and filter as this provides an instant visual.
As mentioned above if the plunger is soft and does not firm up after a couple of pumps you are sucking air.