[Jrienzo4]

Hey guys, I am running an '83 F350, 460, with carburetor and mechanical fuel pump. Recently the fuel pump went out and I replaced it with a new one from O'Reilly's. Well the pump cannot keep up with the fuel consumption on the highway - not even without a load. So I am assuming I got a fuel pump designed for a 429 or something... Now I am planning to order one from Summit. Can anyone tell me the correct PSI and GPH for a stock 460? I want to be sure I get the right one this time.
Thanks.

 

[wickettoby1]

The engine ran great before the fuel pump went out? Do those trucks have an electric pump back at the tank to push the fuel up to the mechanical pump?

 

[xoliex]

I've had an Edelbrock mechanical pump that worked great when I was having issues with a stock style pump from Pep Boys. I only had a super mild 460 build at the time.

 

[Werecow]

Wondering if you've got a dual tank set-up?? Those can be problematic... If so do a search here and see if you may have some of the same symptoms as others here and if so maybe they found a cure for your ails as well??
Check "Runs out of fuel" thread by @Fridayschild and see if that's maybe it??

 

[Jrienzo4]

So yes I have a dual tank set-up, and yes the truck ran fine before the fuel pump crapped out. You see the truck had pumps in the tanks that evidently stopped working the previous owner installed a mechanical pump instead of of pulling the tanks and replacing the original pumps. I've had the truck for a year no issues... But recently the mechanical fuel pump started pissing fuel out the weep hole. So I replaced it. Now the fuel pump cannot keep up at 55mph. I'm pretty sure it has to be the pump.

 

[wickettoby1]

So the mechanical pump is having to pull fuel through the electric pumps in the tanks?

 

[Jrienzo4]

So the mechanical pump is having to pull fuel through the electric pumps in the tanks?

Yes.

 

[Fridayschild]

Fridayschild here. Mine was an '85 E350

Turns out my issue was a combo of things, first the regulator was not functioning, then when pressure was correct the volume was too low. There was a kink in the fuel line from the tank where it exited the pump assembly, then the tank selector was malfunctioning so gauge was not accurate. Solved all those to find the new rail pump was not pumping enough fuel. Replaced that with an Edelbrock pump. Mine needs about 35-38 GPH and 7# at the carb which is a new Holley 600cfm.

So, check fuel pressure, and volume at each component. Holley also suggested a clogged fuel screen in the inlet fittings at the floats but that was not an issue.

Depending on the condition of the tank pump assemblies, you can just replace the pump itself without replacing the assembly. Front assembly is still available, I think I got the last rear pump assembly in the world. Took 6 months to find it.

Good luck!

Kimberly