I have a 2008 6.4 that stared to have very long cranks when I turned the key. The batteries are new and fully charged.

I noticed that if I left the key on for awhile, it would start up normally, and be fine the next few starts unless it sat for a few hours. I figured it was losing prime. When the truck ran, it had full power, not bogging everything was good.

I changed both fuel filters, and ensured they are tight. Check water in fuel separator, pulled the lever off and both holes are clear.

Fast forward to today, truck shut off on the side of the road. Not getting fuel at all, finally getting low fuel pressure and rail pressure trouble codes. The fuel tank is low, and I was on my way to the diesel station but not out I'm going to add fuel as a first step just in case). I opened water in fuel separator and fuel came gushing out. Truck was towed to my shop, now I need to figure out where to start.

Mods: DPF delete exhaust, AFE intake, spartan tuner.

Any ideas? Thanks!

Joe

 

do you know the number for the codes? if leaving the key on for a while before starting helped the start i would think it had some air intrusion like you said loosing its prime. did you use ford filters? new o rings? how was the old filters? any water out of the water separator?

 

I do not remember the codes off hand, but they all had to deal with low fuel pressure.

I will re-check the codes when I'm back by the truck. The one thing I didn't try was the fuel reset button, but that doesn't explain the bleeding down. I used motorcraft fuel filters, and new o-rings. I think I'm going to get two more and replace them both again and make sure the seals are good.

The old lower fuel filter was pretty clogged, I just got the truck and so it may not have been changed for a long time. The upper one looked brand new, and there was no metal or rust in the bottom. When I first got the truck a couple of ounces of water came out the separator, and I drained it again just a few days ago when I started having the same problem. There had been about 3 months and 8k miles in between, and less than an ounce of water came out.

 

This sounds like air in the system. Other causes is perhaps a bad lift pump.

 

So apparently the no-start was due to fuel level to low in the tank. It was registering on the gauge, and said 35 miles left. I don't usually cut it that close and was about a mile away from the gas station when it died.

I still have the long cranks, I'm thinking lift pump.

Going to research how to test the flow rate. I had a fuel gauge on the shreader valve to bleed the system. It showed about 3 psi, but I was getting almost no flow.

 

There are some youtube videos out there on that I think, do some searches. I try to till up as soon as the 50 mile warning comes on.

 

I had a similar issue on my rig, DTC was P0232 fuel pump secondary circuit high. Long story short it is the horizontal fuel conditioning module (HFCM) "lift pump". What year is your rig? I was fourtunate enough to get mine replaced under warranty. My dealer is also mod friendly.

 

My truck is out of warranty now. I actually was happy to find an 08 with low miles, a clean oasis report, and out of warranty. That means someone didn't drive it enough to mess it up before I could pull all the bad stuff off.

The truck is actually starting and running like normal now. I replaced both fuel filter and o-rings again, and used a lot of grease on the rings. Seems to have fixed the problem. Must have been air admittance somewhere.

 

Thanks for reporting back.