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Two days ago I change both of the fuel filters in my '08 F250. This is the 5th time that I've changed both filters and I've never had any issues afterwards. This time, however, the truck won't stay running. The filter changes went good, nothing out of the ordinary happened. After the filter changes I cycled the key from off to acc 6 times and when it turned the key the truck fired right up. After running for about 3 seconds the truck sputtered and died. I repeated this process several time until the battery eventually went dead. I recharged the battery yesterday and today I pulled the caps on both of the fuel filters to make sure that the seals were good and that there was nothing preventing them from sealing, they look good. I also made sure that the water separator is closed and not leaking. I repeated the bleeding and starting process 3 more times today with the exact same result, runs for 3 seconds then dies. Every time that the truck stalls out I have to repeat the bleeding process in order to get the truck to fire up the next time. If I don't bleed/prime the system the truck won't fire up.
Anyone have any suggestions on things I should try?
new o rings were used?
both were lubed with diesel fuel prior to installing on the caps?
the upper fuel filter has an X on it as does the cap. Make sure it's not binding.
if all else fails remove it all and start again
6.4's are notorious for air-locking the fuel system after filter changes if not bled properly. Just cycling the key several times will usually not work. Best way to do it is to remove the Schrader valve from the test port on the fuel cooler after changing the filters. Run a hose from the test port into a fuel can and then cycle the key. This gives the air in the system somewhere to go rather than being forced through the system. You can try this now but it likely wont work as the truck has been started with air in the system which is likely now trapped in the high pressure side. Best way from this point is cracking the HPFP return line at the fuel cooler and cycling the key until no more air comes out. Will likely take a few cycles. Unfortunately without the Ford special tool for bleeding it is going to make a mess. The return line is the rear fitting on the cooler.
new o rings were used?
both were lubed with diesel fuel prior to installing on the caps?
the upper fuel filter has an X on it as does the cap. Make sure it's not binding.
if all else fails remove it all and start again
I've checked all of the above, twice. I already restarted from scratch once. I checked every inch of the seals to make sure that neither of them are damaged and I lubed them both with diesel before replacing the caps.
I'm not sure about the x on the fuel filter but I ensured that it's oriented properly and not interfering with the cap. Both of the caps are tight and I don't see any fuel leaking anywhere.
6.4's are notorious for air-locking the fuel system after filter changes if not bled properly. Just cycling the key several times will usually not work. Best way to do it is to remove the Schrader valve from the test port on the fuel cooler after changing the filters. Run a hose from the test port into a fuel can and then cycle the key. This gives the air in the system somewhere to go rather than being forced through the system. You can try this now but it likely wont work as the truck has been started with air in the system which is likely now trapped in the high pressure side. Best way from this point is cracking the HPFP return line at the fuel cooler and cycling the key until no more air comes out. Will likely take a few cycles. Unfortunately without the Ford special tool for bleeding it is going to make a mess. The return line is the rear fitting on the cooler.
I didn't have time to look into this today but tomorrow I'll give it a shot.
If I wanted to try the first, less messy, method first which of the lines in the photo is the Schrader valve and test port?
I didn't have time to look into this today but tomorrow I'll give it a shot.
If I wanted to try the first, less messy, method first which of the lines in the photo is the Schrader valve and test port?
The Schrader valve is the line in that picture that has the threaded barb coming off of it. You can buy a Schrader valve removal tool from an auto parts store for a few bucks.
This has happened to me before. The fix was to change filters again. Apparently every so often we get a rogue filter.
*UPDATE*
I decided to start the filter change over from the beginning and I also went a bought new filters. I don't know if the other filters were the actual issue or not but after installing the new filters and priming the system 15-20 times it fired up and is running good.
At this point I honestly don't know what the actual issue was. It might've been one of the seals, though they both looked good. Maybe it was just a bad filter, they are motorcraft, just like the new ones. Maybe I had an air pocket that I was finally able to push through the system, even though I've primed it a lot over the last 3 days.
At this point I am just glad it's back on the road, and without having to make a huge mess in the engine bay and under the truck.
I appreciate everyone taking the time to read and respond!
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