My 77 Ford F-250 Super Cab Camper Special (351M) has a reaccuring problem: It feels like its running out of gas (but is full) and dies. Last year this happened with crazy backfires, but this time no backfires. I got it running well with new ignition coil, spark plugs/wires, and distributor (cap, rotor, and dist). This time they tell me my three year old battery is bad - replaced it and all the other stuff (except the distributor itself), poured some gas in the carb and it started. 1/2 mile down the road it starts the herky-jerky loss of power and dies. I put more gas in carb and started it up but this time it billowed black smoke from exhaust and died. I was blocking traffic so started again with same result. Please help me! I think it's the fuel pump or eccentric because when I try starting it now no gas is flowing through the line - but whats up with the black smoke? Am I going to destroy my truck with further attempts? Thanks.

 

First off, welcome to FTE.

Now, replace the fuel pump. Even if that's not the problem, that's one less thing to go bad in the future. If a new pump doesn't solve the problem, make sure your fuel lines aren't clogged. Have you ever changed the fuel hoses? It would be a good idea to.

As far as the smoke, black indicates a rich condition. It's not incredibly great for your engine, but it's not gonna hurt it.

 

Before you replace the fuel pump a few questions/diagnostics.

1. What carb? Eddy's and Holley's don't like the pressure that a stock mech. fuel pump puts out. That might be your black smoke problem. Black smoke=mixture problem. Although you did say no fuel coming out of the line... I'll leave this here for your future refrence.

2. Check your pump output. I can't find my manual ATM but you should have more than 8psi, and I'm not sure about the GPM that the pump should put out. There could be a chance your sucking sediment from the bottom of the tank, so install a remote line to the tank side of the pump and have it sitting in a container of gas. Have the carb side of the line with a pressure gauge the end and crank the engine, away from open flame. This first test is for pump pressure. Then, have someone crank the engine, and let the gas pour into a separate container and check it against specs. If it checks out okay, proceed to 3. If it fails to have the proper output but sucks gas, proceed to step 4. If it really doesn't suck gas at all, proceed to step 5.

3. How long did your truck sit before you started it? My guess is theres a bunch of crap in the line. Same thing happened with my truck. I have 3 filters on it now, 1 right after the tank, 1 before the pump, and 1 before the carb. Try blowing out your fuel lines and trying again. You may need a new tank/lines but can get away with a butt-ton of filters for the time being.

4. You're here because your pump isn't doing its job. Can you see gas shooting out the vent hole on the pump? If yes, you got lucky that your pump failed this way. You need a new pump. If not, pull your dipstick, theres a good chance it smells like gasoline and is high. This is because the diaphragm ruptured, and now your pump is dumping gas into the crankcase. You're a little less lucky, because now there's the chance that you got oil wash and you could've scuffed your bores. Sounds like this came up fairly recently, so I'm not sure it'll really affect you. Either way you need a new fuel pump.

5. Your cam lobe may be flat. Stick a dowel in the fuel pump hole and see if it moves out when you rotate the engine. If this is the case, you need a new cam cos the lobe is flat.

By the by, welcome to FTE!

 

Sounds like you could be of some help. Someone syphened my gas, ha! put gas in it and down the road. The big clouds of black smoke has me worried though. What about the head gasket leaking, and does it matter that when it happened I was on a steep grade.Then my starter went out two days later, and the guy said it was due to a bad battery. Then two days after fixing that, I notice an oil leak on the floor in the cab passenger side and get a face full of white smoke going to work that day. Buddy says its the heater core and its not oil but antifreeze (I still swear its oil). Every year about this time my truck makes me prove my love for it. How easy and inexpensive of a fix is my heater core, if you think that is what it is. Thanks for the input, and glad to be a part of forum!

 

Leaks on passenger side floorboards are always the heater core. There isn't anything else over there to leak. I don't know where you live, but if a heater isn't a requirement it can be bypassed "easily and inexpensively". Easy and inexpensive are not words I've ever heard anybody use to describe heater core replacement. I need to do mine right now, but I live in Arizona. Not high on my list of priorities, so I just bypassed it