I don't have any answers but we're in the same boat. Both diesel mechanics I've spoken to said we are looking at replacing the entire fuel system. I found a video on the topic and Ford recommends replacing the fuel system when these types of problems happen. I was quoted 8-10 K by one mechanic and 6-8K by another mechanic. I reckon we are going to be buying the parts and he's going to try and do it himself. I'll be researching and looking at everything I can find to help us out. Everyone keeps saying the 6.4 isn't worth fixing but I've looked at truck prices and there's nothing available with this towing/engine power for what it's going to cost to fix it. Plus she's only got 208K miles on her. We're going to put her on a trailer and haul her to the lower cost mechanic. He said he would diagnose it and be certain for $125. My thing is CAN I get the parts cheaper than the $4K kit I'm finding online. Separately the parts don't look that expensive. Trying to figure out why the kit is 4K. Be great if anyone working on replacing the fuel system or has already successfully done it to share videos/advice/etc. I'm better at reading and researching and he's better at doing the actual work so it's a team effort over here for certain. I already read one story of one man on here who did the fuel system replacement and it went terribly and he lost a lot of money. I believe he paid to have it done so this is stressful to say the least.

 

From everything I've researched and re-reading your post, I would note that everything I've read says do the entire fuel system at once or you'll never fix it. You've already done the pumps, frp regulator and filters. If the research I've done proves true then you may have to redo all that. My initial plan was to do it part by part like you're doing but research indicates it re-contaminates the system and ruins the new parts. I'm no mechanic. I'm just good at reading and researching to help my mechanic fiancé.

 

Sincerely appreciate the reply. Yeah, I’ve been making my way to starting this project but haven’t got into turning wrenches yet. It seems like a full fuel system replacement is the standard reply to any of these questions. But you’re on par with the clean/replace aspect of this. It would be a defeat to go through all this only to crank it back up and have the problem persist because you got lazy and didn’t clean something.

 

Had a guy in a Facebook group tell me to replace the oil pressure sensor

Ok. So, I apologize if I’ve led you down a bad path. I put the oil pressure sensor on the truck and it was running like a champ and then went right back to doing what it had been doing in a 30 mile trip today.

🤣🤣 good ol FB groups

are you guys typing all those words or using text to talk? Because that’s a LOT to read.

 

I'm on a computer.

 

Here is some advice on HPFPs. First, I lost mine a 280K miles. I was always regular with a diesel lubricant and that may have helped achieve those miles. If you are going to DIY make sure you have sourced a HPFP first. If turning it over to a mechanic, ask when he can get one. Bosch discontinued producing them several years back. The only way I was able to get one was to wait 9 months for a quality rebuild. My Mechanic's experience with remanufacturers told me which to stay away from. Like turbos there are quality rebuilds and there is junk. A good idea is to ask the diesel part companies who does the best work on them.

I had him replace the injectors while it was accessible as well as replace the primary filter/pump, lines, and clean the tank. During the job I had him replace a water pump, replace the thermostat, check the belt tensioner (used to be a weak point), and inspect the valve tree. The 6.4 bathes the tree with oil. Some think that was a short cut as opposed to direct oil injection lubrication. Oh, read up on how to get air out of the cooling system to avoid cavitation.

Good luck

 

Just Wow! Thank you for sharing.

 

Were your fuel rail pressures reading accurately?