My 78 cut out on me the other day so I put gas still didn't start .I drop the tank right now put a new fuel pump still doesn't start! I'm check the power to gas tank and seems like there isn't any power to it. Can anyone tell me why or if there is a fuse or something that can go out? ......

Thanks for your time I would apprcate a fast replay I'm under the truck out side in this dam rain. Thanks

 

It sucks no one replied but here is a thought, my 78, and I am sure yours is the same setup, the feul pump relay gets its power from an oil PSI relay. The reason for this is so when the engine stops running, like in the case of an accident, the fuel pump stops as well... So, I would check the fuel pump relay, which is mounted to the stearing colum under the dash. Its the only relay attached to the colum. Second, make sure you are getting oil pressure. Is the oil PSI light going out when you crank it over? Lastly, I put an in line fuel PSI gage just aft of the fuel filter. I would recommend ANYONE who has one of these old vehicles to do that. It eliminates a TON of troubleshooting.... Just my thoughts about the whole thing... I am sure there are many more out there who just missed the post that could offer more than what I am saying. But hey, its a start... good luck!

 

I dont know much about the older toys but Id imagine just like anything else electrical trace the wire until you pick up power again and thats most likely your issue.

However if your gas tank is pulled from the truck and your trying to start it I dont think it would since its not grounded, or atleast with my truck that was a factor it had to be bolted back in to make ground.

 

when you were troubleshooting (before pulling the tank).. did you detach the oil pressure sensor and listen for the pump?

 

So I'm reading through older threads, and I assume you aren't still under the truck in the rain. How did this turn out?

My first thought is that you have multiple people talking as if there's a fuel pump in the tank. If it's fuel injected, this is true, but for a '78??? Really? Wouldn't that have a mechanical fuel pump on the side of the head driven off an eccentric on the cam shaft?

If that were the case, I'd rig a temporary header tank. Something like quart can and some gas line hose and some fittings to make them go together, or maybe the right sort of funnel. Then I'd hang that from the underside of the hood over the fuel pump inlet and see if that worked. If I could find my spare, I'd include a small fuel filter and use very fresh gas. Figure out what works, then add parts of the old system back in until it doesn't work.

But you said you replaced the fuel pump. If you did that, there must have been one there to begin with, I guess.

 

elect pump ?

This an old thread but out of curiosity about your truck ........ The '82 and '86 we have are both 22R gasoline with a mechanical fuel pump (cam driven) Tell us more about your truck. 82LBUSA