1976 FJ55 fuel issue

[martinjbradburn]

My 76 FJ55 has a problem.

When I drive around town, the truck runs great.
At about 50 mph (this is a guess since the spedo doesn't work) the engines starts to knock and rattle, but still runs.

After 60 mph when i am catching up with traffice, the truck loses power and acts like it is not getting fuel.

If I slow down to 55, it runs.

Just got the truck a few months ago and it has an electric fuel pump.

My question is;
Is my diagnosos accurate?

Should I get a bigger electric fuel pump? (not sure of the size now)

Should I go with a mechanical pump?

I am open to suggestions, as long as it doesn't have to do with fuel injection or propane conversion.

 

[3_puppies]

have you checked your fuel filter?? follow the lines and make sure someone didn't "add" an extra filter somewhere along the route.

Is the electric pump running thru the mechanical pump?

 

[ToyotaGuy88]

I had a problem with my 40 hesitating when i first bought it, it had a electric fuel pump so I swapped it out for the mechanical and it helped.

 

[martinjbradburn]

Funny you say that about the added fuel filter. There is one. I didn't understand but maybe I will take it out. It is on the line between the gas tank and the electric pump.

I think the mechancal has been removed, but I will check again.

 

[40Flipper]

I had a problem with a filthy air filter that choked my speed down when I hit 45 mph. New air filter fixed it