hawg20

97 F-150 96,xxx miles 4.6 Auto 4x4. Truck starts fine on level surface, starts fine when facing down an incline, won't start when facing up an incline, cranks, but won't fire. It can be sitting up the incline for less than 1/2 hr and won't start. If you roll it down to a level spot, it will eventually start and run? Never had a fuel injected vechile act like this before, don't know what to think. Looking forward to hearing any and all suggestions

HAWG20, MOANG retired

dewman

Welcome hawg!

Possible fuel pump issues? Sounds a little odd to me too.

05 super

long shot here, but is there something heavy in the tank that plugs the line out of the tank when facing uphill? but rolls out of the way when level or downhill. i know it's a long shot.

dewman

I, personally, have never heard of anything like that, but...

05 super

i,ve seen it in our tandum dump trucks, when a rag has "fallen in" to the fuel tank. the truck would run fine and then it would lose power. the rag would move in the fuel tank and plug the fuel delivery. i know that a rag couldn't get into a gas tank filler, but has a float or something fallen off in there. he asked for all and any suggestions.

dewman

I suppose anything is possible, I have just never heard of anything breaking loose inside the gas tank(s) and blocking the fuel line.

05 super

like i said it would be a long shot. what i was thinking is that it only happens when he's facing uphill, so if the fuel delivery line is at the back of the tank something must be rolling back and plugging it. that's why to me it seems like a fuel delivery prob and not an electrical prob.

hawg20

Update: Finally the truck would not start at all, turned out it was the fuel pump, replaced it and I have had no problem for months. Thanks to all who helped!