My truck will start, idle, run great, then after driving a few minutes, it dies like its out of fuel. Does this mostly between 30-40mph but has done it at higher speeds, never at a stop. Sometimes it will start right back up, sometimes it has to sit for a few minutes. Coil, fuel filters (both), spark plugs, wires, and distributor are new. Carb was rebuilt last weekend, but I did remove a spacer that was not the right size.

'82 f150, 302, 2150 motor craft carb

 

Welcome to FTE.

Dies like it's out of fuel - in that it sputters for a second or two and then dies?

Check your fuel pressure & output rate at the carb.

 

It will lose power and decelerate then just die. It happens randomly but increasingly do today. At one point I was able to control it by letting of the gas pedal when it started to sputter then accelerating again over and over until I was able to get off the highway and turn it off. I'm brand new to fixing trucks as I bought this truck to be my introduction to it, I'll have to look up how to do those things you suggested but I appreciate the help greatly.

 

Have you checked the rubber fuel lines? I've had one 82 and two 81's, all of which had bad, rotten fuel hose. So bad that some of them oozed gas right through the side of the hose, and also allowed air to get in, and the air kept the fuel pump from supplying enough gas to run the truck very fast or very long. There's a hose on top of the tank and one from the hard line to the inlet of the pump. And, if you have dual tanks there are hoses from the hard line to the valve.

If you do replace the hoses get the new fuel line that is good to use with ethanol. I think the lettering on it is green, but I'm not sure. Anyway, I think it is time and ethanol that has killed our hoses, but I've sure seen a bunch of bad ones.

 

I do have a dual tank, and I'll be sure to check that in the morning Gary. I haven't seen any fuel leaking anywhere but then again I just realized the fuel pump is on the engine. (Thanks for showing me just how little I know Haynes Manual) I did notice that the inline fuel filter (that is clear) wasn't getting any fuel in it after it died, but it did start right up after sitting a while and the filter would fill right up.

 

You said you've replaced both filters. Where is the other one? I run two clear filters - one ahead of the pump in place of the tank selector valve and one between the pump and the carb. The first one protects the pump, and on trucks that have sat quite a bit usually has to be changed frequently as it catches a lot of rusty silt.

If you need to replace the hose on top of the tank, and I'd bet you will, there is usually enough length on the bolts holding the tank on via the straps to let you get to the hose w/o taking the tank out. And, make sure that all of your connections are tight as any leak ahead of the pump kills it's ability to pump.

If the hoses don't seem bad it may be the pump. Chris is right on with his suggestion to check pressure and volume, and from what you've said it does sound like a fuel problem.

 

The clear one between the pump and carb and a cartridge that screws into the carb itself. So did you just remove the tank selector valve with a filter? Or add one in addition to the valve.

 

If the cartridge you refer to is the standard one and not a really high-dollar special one it is almost good enough to catch gnats, but nothing smaller. I've taken the apart and even the Motorcraft/Autolite ones are nothing but a screen. The paper filters have much better filtering capacity. MUCH better.

I took the tank selector valve off and replaced it with a clear filter connected to the front tank. I don't use the back tank so don't need the valve.

 

That's actually a great idea, I think I'll do that while I'm looking for fuel line leaks.

 

Lines looked like the PO recently replaced them. I'm going to get the stuff to check the pressure after church.

 

Finally got under the truck again, fully expecting to change the fuel pump and I noticed a small drip where the fuel line met the pump. Tightened it up, and now it's running good, well other than bogging down when I go over 60mph, but that's another post. Thanks for your help guys!

 

That's what I was talking about. Any leak at that point lets air into the system and kills the pump's suction. Well done. Now, on to the next problem.