Guys, I just did a quick service call on a '12 F350 that shut down while running on the highway. It was like shutting the ignition switch was turned off. I couldn't do much on the side of the road and the owner is arranging his own transportation to the shop. The only code was low fuel pressure at the fuel rail during crank. He is concerned about the hpfp going bad. I will have to get it here before I know much more.

FWIW, I noticed a high pitched squeal coming from the lift pump (frame mounted). I am replacing it first since I believe that's going to be the culprit but I still am curious. Those of you who have had the high pressure pump go belly up, did it die immediately with no warning or was it a gradual event?

 

Plugged filters is possible.


More common is the little card board piece from the cap it he adds an additive.


The little card board will come off the cap and then you go to pour the additive in the tank and the card goes in there too.


Gets sucked up and plugs the feed.


I would doubt it to be a hpfp just yet.

 

HPFP failure is not as common as one might think. Failure is more often from water than other reasons.

 

Agreed, in reading this and other forums you just don't hear about it much. Not nearly as much as the issue is made out to be in the 6.2 vs. 6.7 threads

 

I have an update. I didn't like the sound of the fuel pump. You could hear it squealing what seemed like a block away. I replaced the low pressure fuel pump. It is quieter but not as silent as I think it should be. Still no start so I went into the electrical system. (this truck quit like the ign key was shut off). We checked all fuses, and verified the pcm relay was good. I checked fuel pressure when cranking and the high pressure showed 6200 psi during crank. Still no start so we went back to the low fuel pressure during crank. I removed both lines coming from the tank at the filter and connected a fuel line to both nipples and put them in a 5 gallon can of fuel just to eliminate the tank. During cranking we lost hp fuel pressure. The best we can get is 405 psi. Before this I pulled a connector from a injector and checked for voltage both with ign on and crank. No voltage, I used a noid light and no flash. I don't believe the pcm is firing the injectors and need to find out why. During crank the low fuel pressure goes from low to not low. I'm beginning to think the fuel pressure sensor is bad.

So, I am not that familiar with a 6.7 system so I am asking if the fuel pressure sensor could be causing the no start.

Like others I don't believe the high pressure fuel pump went belly up that quickly. The truck ran fine with no issues until it shut off while running down the road. Any insight would be helpful if you have any ideas.

Another thing that bothered me is the amount of fuel pressure and volume from the low pressure pump. It had very little flow and although I didn't check pressure with a gauge yet I doubt it had much more than 10 psi. I was a little surprised at that. I will be researching what it's pressure should be but I am hoping that's what it should be. The new pump came from our local Ford dealer. In matters like this I only use factory parts if possible.

Any ideas at all would certainly help.

 

I'm with Senix, did you drop the tank and make sure there isn't a little round piece of cardboard from an additive bottle in the tank? It's stupid that the additive bottles have them and they fall out really easily - the opening for diesel is really large and it's easy for it to get in the tank and it's just the right size to almost block the flow of fuel.

If you did and are still having these problems more troubleshooting will surely be needed.

 

I had that issue on my mind the whole time. That's why we took a five gallon gas container and filled it with diesel and ran both pick up line and return lines into it. We had fuel flow but not what I thought is should be. Fuel tank was completely out of the picture.