GEN 2 Engine starts and stops right away

[GordoJay]

Wow, that's good to know. I've taken mine down to 30 miles to empty. Guess I won't do that on purpose again.

 

[Pralix]

That does seem odd, how much of an incline are you on? because it does sound like the pick-up wasn't able to get enough fuel.

The truck reads 6 degrees.

 

[Pralix]

I’ve had the same thing happen to me on my 2020 on two occasions. Been to the dealer for it twice with no fix. Both times I had at least 8 gal of fuel

Nice to know. Were you on an incline? I hope this doesn't happen going down a long hill...

 

[Pralix]

Also, the truck doesn't shudder or make stalling noises when this happens. It just shuts off. Possibly some protective measure for what it is deeming to be low fuel or low fuel pressure or any of the other things it could be in the fuel system. It should not be doing this.

 

[GordoJay]

Also, the truck doesn't shudder or make stalling noises when this happens. It just shuts off. Possibly some protective measure for what it is deeming to be low fuel or low fuel pressure or any of the other things it could be in the fuel system. It should not be doing this.

Maybe it should. I've heard that you really don't want to run a fuel pump dry, the fuel is the lubricant. Burn up the pump and you're dropping the gas tank. That isn't cheap.

 

[Pralix]

Seems like this is a known problem with the Ford F-150 fuel system. I guess the 36 gallon tank is so big and the fuel lines are so long that this happens. I don't agree with Ford's advice to not park on an incline and to never let it get down to 1/4 tank. It almost seems like there are no 8 gallons of fuel that you can't use because of the fuel system.

This thread in another forum seems to explain the situation:

https://www.ford-trucks.com/forums/1524554-2018-f150-fail-to-start-on-hill-3.html

 

[richnot]

On a SCREW Is the fuel pickup/pump in the front, middle, or rear?

Maybe Ford should try using something like this, other companies do make them for stock fuel pumps

https://www.holley.com/products/fuel_systems/hydramat/

 

[Pralix]

On a SCREW Is the fuel pickup/pump in the front, middle, or rear?

If I had to guess, rear or middle.

 

[OriginalToken]

Today I was getting ready to go out in my 19 Raptor. I keep it backed up my driveway which is an incline. The fuel gauge showed 98 miles left. I started it and it ran for awhile and then shutoff. I got a message about auto-start stop needed to be reset. Then I got a low fuel warning and the miles left dropped down to 47. I started it again and it ran for a couple of seconds and shut off. There was no rough idle. Start it again, same thing. Over and over. My uncle brought over some gas and I put half the can into the truck, probably 2.5 gallons and it started and kept running. Weird. I then take it to the gas station to fill it up and I put 24 gallons in before the pump cut off. It seems like I had plenty of gas in the tank and this should not have happened. Has anyone had this happen to them? What could it be the issue?

My take on this, and I freely admit my take is nothing but a guess. To me it sounds like you were down to less than 10 gallons in the truck when you parked it. It saying you had 98 miles DTE on parking, what is your average MPG? For me 98 miles DTE would be in on the order of 7 or 8 gallons left under average conditions, maybe as low as 6 gallons left, generally not as much as 10 left. And you parked it on a hill facing down.

Both of the Raptor tanks, the 26 G and the 36 G, are long, narrow, tanks. The 36 gallon tank is over 6 feet long and only about 20 inches wide. The fuel pickups for both sized gas tanks are behind the center point, i.e. closer to the back than the front. Both tanks have a shallow well or depression in the area under and around the fuel pump and pickup. This well should keep fuel centered around the pump with the vehicle in motion and sloshing, even with a nose up or nose down attitude.

None of the below images are mine, I grabbed them off the web. I did add the lines and the angles.

These are the two tanks, the 36 gallon tank is the one in the back. The left side of the image is vehicle forward, the right side is vehicle back. The white'ish round section on top of each tank is the top of the fuel pump / gauge / pickup.


Below is the tank with a notional fuel level in it, call it a bit less than a quarter tank. You can see that the fuel pump is the lowest part in the system, with the bottom everywhere else sloping towards it.


Now I have rotated the fuel tanks 6 degrees vehicle nose down, leaving the red lines alone. The fuel pump well is no longer the lowest part of the system. The "nose" of the tank is significantly lower than the fuel pump, and the fuel has all shifted towards the front, away from the pump


To me it looks like the system is biased towards the rear. I mean if the fuel shifts rear wards the system continues to pick the fuel up well and the shape of the tanks minimize bunching to the rear. This makes sense to me. Under acceleration or going up a hill is the worst possible time for fuel starvation so you design to reduce that risk.

Ideally, of course, you would cover all bases and have no "bad" conditions, but real world engineering is managing those risk with realistic solutions that fit the mechanical requirements of the system. You fit it where you can and make it work the best you can in that location.

I see the same issue, but reversed, filling the tank as draining it. I have noted that I can put a little more fuel in the tank if the vehicle is slightly nose down than I can if the vehicle is slightly nose up.

T!

 

[Pralix]

The truck says my average MPG is around 13.