I have a 1984 F-250 4x4 460 CID. This truck is a thirsty work horse only used for hauling our camping trailer or boat, hence it sits more than its driven.

I have two problems.

SOMETIMES after starting(wich requires a lot of peddle pumping) the truck belches black smoke (too rich)and will not idle. Turning the idle up will keep it running. Then, (sometimes) after a 20-30 mile drive it purrs like a kitten and now the idle is too high, I can turn the idle back down and things are fine untill the next time it decides to act up. It has got to the point of instead of saying I'll get the truck, its, I'll go see what mood the truck is in. This has been going on for over a year now.

2nd problem just started on my 50th birthday(AUG 20) while trying to get to the lake with the boat. The rear fuel tank will not work. I found a relay that clicks when you go from center of the selecter switch to front tank but not from center too rear tank. The guy at NAMPA told me he would sell me a new relay ($25) but if that was not it it was still my relay and to go home and try swapping relays(at least 3 of the same type on truck). well that sounded like a good idea but i could not find the other relays. durring my search i discoverd that i have electric fuel pumps in the tanks. (this is actually my girlfriends truck, i'm just starting to dig into it) I saw something on the net durring my search, wich led me to this site, concerning the in tank pumps and check valves which, if bad, allow fuel to flow from tank to tank or some such thing.

I am now thinking (watch out) that maybe my first problem and the new one could be related.

Then again i might need a new carb and fuel pump.

I have put of getting a new carb because of the cost (~ $400.00) and i just cant believe a come and go problem could be in the carb.

SOMEBODY HELP ME PLEASE Thanks

the 50 Flathead purrs like a kitten all the time

 

Well, you are right about the black smoke meaning it's too rich, but pumping the gas pedal is just making it worse, Everytime you push the pedal to the floor, you are squirting gas in the engine. If you think it's flooded, hold the pedal to the floor and crank it. This will also kick a lever which should manually open the choke if it's stuck. On a truck that old, I would suggest getting the carb rebuilt. Have you checked around any of the shops and see how much they would charge to rebuild the carb? It would have to be cheaper than 400.00. Also since this truck sits around, you could have rust in the fuel tanks. This could cause intermittent flooding if the fuel filters are not changed on a regular basis.

 

 

heres what i think the problem might be check for fuel pressure in the rear tank. If the rear tank doest get used alot the tank can draw moisture and cause rust in the tank and it can also take out the fuel pump. Try to change the fuel filter and then check for pressure on the rear tank. If theres no pressure there then its more than likely the fuel pump in the rear tank. The fuel pump could be going out on it as well.