Augster

Went to Big Bear on an extended weekend vacay and after arriving Friday morning, a day of skiing, then afterwards parking at the rental home, the truck sat until from Friday afternoon until Sunday morning. The temperatures ranged from a low 30's at night, to the high 50's in the day through this period. On check-out day, with the morning temps high 40's/low 50's, attempted to start but it would only crank but not start. Checked 20A fuse cartridge #70 (truck has the Fuel Pump Relay fix installed) and it was good, but replaced it anyways with a brand new spare. Even jumped the truck (though the starter spun quickly and showed no signs of sluggishness) but truck still would not start after numerous attempts. 45 minutes later we gave up and decided to have AAA tow it back home the next day (we left truck at tow yard while I jumped into one of the SUVs in our group to head home). When it was finally delivered today just afternoon, and I went out to start it without doing anything else to the truck, it immediately started; temp was about 68-70 at the time.

So now I'm stumped and concerned on what caused the issue as I can't trust the truck anymore, at least in cold weather, until this is solved. I'm going skiing again in several weeks so I want to get a handle on this before then.

Anyone have similar experiences and/or fixes?

My suspects are either a marginal relay (I swapped the tow parking lamp relay with the fuel pump relay for now), failing Fuel Pump Driver Module, and/or failing pump, with these failures so far only exposed in cold weather.

Envious

Did you get the battery tested? I was having a lot of weird issues and it turned out to be a bad battery. Just because it starts the truck doesn't mean it is healthy and will start after a cold soak. I thought mine was good but when it was tested it was only putting out 600CCAs compared to the 850 it should have been.

Augster

Although I didn't test the battery, we jumped the vic and kept it attached for at least 20 minutes during our testing and it still didn't start.

Besides, battery was replaced about 18 months ago. Since getting it towed back, I've driven it several places totaling about 50 miles and so far it runs fine.

I left out a few important details in my original post in that when I inspected the original 20A fuse cartridge, I couldn't really see clearly one side of the fusible link; it looked kinda of blackened (didn't have my old-man reading glasses) and when I popped it out with a screwdriver (too cold and too stiff to pull out by hand), it went flying somewhere into the engine compartment. In addition, my brother-in-law had his Bluetooth OBD adapter and diagnostic app on his phone and it said there was a fuel pump fault. He tried clearing it but afterwards there was a Wrench icon on the gauge display, which disappeared after I removed the key and reinserted. I assumed the fault was a result of me pulling the fuse, though I immediately replaced it with a new one.

Without further guidance, I'm going the scatter-gun approach and went ahead and ordered brand new relays, fuses, and Fuel Pump Driver Module and will replace all when they arrive.

maco

My money's on the fuel pump driver module....It will do exactly as you described !!
It took a (almost 6 months) before mine was replaced & that was more for sluggish poor performance...
It would not start on numerous occasions & I would pop the hood & do silly almost stupid things like remove battery cables going to the engine fuse panel...
clean & reinstall & it would start right up !! (Till the next time !! as in many) No issues in the next year or so!!

Augster

That's my bet, too. Reading up on the FPDM, its purpose is essentially a voltage regulator, and its pending failure can result in the symptoms I'm experiencing, which in my particular case could be exacerbated in the cold weather.

hinglemccringleberry

So let me get this straight, you have the fuel pump fuse #27 relocation kit installed on your truck and you STILL experienced a no-start issue related to the fuel pump fuse?

Augster

I have the fuel pump fuse relocation kit installed; not sure if my specific no-start was directly attributable to the fuse, but I believe this fuse relocation TSB was because the existing fuse block was of insufficient capacity to handle amperage which may result in a fire hazard from melted fuses.

I believe it's the FPDM and have a replacement on the way.

Gentcp

Fuel pump module. Mine did the same thing. Would crank, no start, then would start. Started happening in cold temps. Dont get the "upgraded" Dorman one the one I bought was defective. Ended up getting it towed to dealer. Hours of diagnostics later they determined the module that I replaced was bad. Put a Ford one in no issues since.

I messed around with this for weeks, with the fuse kit, relays, etc.

Good luck.

Augster

Just a follow-up closure:

I replaced the FPDM and returned to the same ski resort. After a couple days under similar cool weather conditions as before, it cranked right up with no issues. I didn't change anything else, even though I had new fuses and relays (I've kept them in the glove box in case of another emergency).

So it appears it was the FPDM.