F-150 dying question...

Richard · Oct 10, 2021

My wife's cousin next door, bought a used F-150 from someone he knows. I don't know all the facts but the truck had some kind of issue.... it was disclosed and he bought it.

I don't know the year of the truck (it's older verses newer) It has dual fuel tanks and therein is the issue.

If I understand his problem....he can have BOTH tanks full/empty/moderate and be on the road. The truck will suddenly die on him. Changing to the other tank doesn't seem to fix it.

He's had it to the shop (I think) and the issue persists.....so for probably 1 1/2 years, he's simply left the truck parked in his driveway.

"My understanding" (<--key comment) is this is supposedly narrowed down to a fuel delivery issue, not a filter or pump issue. The problem is intermittent. He might drive 100 miles and all is well.... then he might on a different trip, simply drive to the backside of the farm and it dies on him. So it's not like the problem shows itself after driving "X" miles or "X" RPM's.

He's the happy go lucky type so the truck just sits there and it's doing him nor anyone else any good. This bothers ME much more than it does him as he simply jumps into his F-250 and does what he needs (he bought this so he wouldn't have to drive the 250 around the farm, he'd have a beater truck)

I've not looked at the problem with him as he's so passive about it and our work schedules also conflict a bit.

So with that intricate description, I'm wondering if there is a known fuel delivery issue with an older F-150 model (by the looks of it I'd presume it's 15/20 years old)

I know this level of detail doesn't really help anyone.... I'm reaching for some straws.

K5lwq · Oct 10, 2021

Something sure is strange if it is fuel delivery and no one can figure out the problem. To start with knowing the year and engine would help determine a known problem.

KennyG · Oct 10, 2021

Ok, I'm not real familiar with dual tank systems, but I think there is a fuel pump in each tank and they are switched by switching the pumps on and off. If that's the case, I think the first thing to do would be rig up a switched bypass supply to one of the pumps and see if that will solve the problem. Of course, that is after you check the grounds which are the cause of 75% of electrical problems.

You could also rig up indicator lights to see if the pump is actually getting power when the truck quits.

Roadworthy · Oct 10, 2021

If I get this correctly you want to make somebody else's problem your problem, and the somebody else isn't bothered by it. Is that the gist of it? That's okay, I tend to do the same thing. It would be really nice to know HOW old this truck is. Does it have a mechanical fuel pump in the side of the block for a carbureted engine? Does it have an electric pump? Is it single point fuel injection like a carburetor or is it multi point injected? In short, there's really too little information to solve the problem and intermittent problems are the absolute worst!!

4570Man · Oct 10, 2021

If the problem is the duel tanks and it’s not a daily driver anyway I’d bypass the setup and just use one.

hugo454 · Oct 10, 2021

make sure the gas cap vent isn't clogged or malfunctioning.

TractorGuy · Oct 10, 2021

Without knowing the year you are pissing in the wind looking for answers.

Richard · Oct 11, 2021

Yeah, I knew I was pretty thin on details.

I was hoping on a long shot that "there were three years when Ford had this notorious problem......"

Though I'm not specifically looking to make his issues mine.... he is my wife's cousin.... lives next door (we all live on their heritage family farm). He's not too mechanically inclined (like, at all) I DO like to tinker. If the truck were working, it would be the vehicle we (I at times) would use to toss 6-7 diesel cans in to go fill them up, rather than the trunk of my Camry.

So I have a slight vested interest in getting it going, plus, I always like a challenge. If this were mine, it would have been taken apart already to find issue.

I've even thought about offering to buy the truck off him so that we (all) would have a 'farm' truck, I'd be able to freely get my diesel with it and I could get it running.

I appreciate all who responded, I knew I was grasping at straws. I'll find out more details and ask when I have them.

Boiler74 · Oct 11, 2021

Take a picture of the VIN (base of windshield) and then find a VIN decoder. It’ll tell you year, engine, etc. Then find a Ford truck forum. There are a few. Armed with more knowledge amongst Ford truck enthusiast you might get lucky.

Grumpycat · Oct 11, 2021

First thing I would do when the truck quits running is take the fuel cap(s) off and listen for air inrush or venting. If that happens then therein lies the problem.