1995 f-250 4x4 truck dies at 50-60mph

[dieselsalley]

does anyone have any advice ???? truck has 5.8 engine 37 tires zf 5 speed.165000.miles daul tanks .truck runs perfect at idle and at low speeds .once you start going over 40 mph truck bogs out if you let off gas .slow to about 30 mph no problem .here is the kicker pull out on to the hiway she will pull strong to about 60 then booooooooggggs right out when you pull over she crawls about 5 mph bucking slight poping through the air box if you try to gas it .if you stop and idle for 5 minutes shes ready to go get up to 60 mph then booooooooggg all over again //////here are the things i replaced so far fuel filter,pickup coil,ign module,fuel pressure reg,ign coil,fuel pump,t-stat,fan clutch,air filter,:also the engine light comes on after driving 4 miles i tried to figure out the codes like 23-12-26-17-54-22-46-33-55-42 to me none of these would seem to be the cause ??

 

[tractorman86]

which fuel pump, dont those have an intank pump and a mechanical? has to be a fuel problem, that is all i can figure

 

[snicklas]

How does the exhaust sound? Does it sound open, or does it sound, like I saw on here earlier, like a fat kid breathing through a straw? I had an 83 F150 4x4 351M with the Variable Venturi Carb on it.... it ran so rich it plugged the Cat up....... had no power and would not pull itself much above idle..... after the cat fell off, it ran much better..... just a thought......

 

[dieselsalley]

truck has no cat ..today i replaced computer,and 2 relays under the hood and seems to have solved the problem however i dont know witch one fixed it i think the computer was gone thanks for all advice

 

[tractorman86]

i'd bet it was the fuel pump relay!

 

[FORDMAN41291]

im thinkin either the fuel pump relay for the fuel pump itself.... but it sounds like a fuel pump....