Hi Scotty, i have a 1997 Ford F-350 XL 7.5L Ex-Uhaul Box truck with an automatic transmission.
It runs fine at about top speeds of 40-45mph driving around city streets but the issue im having now is that when try to accelerate on the highway up to 55+ mph it loses all power and starts dropping speed rapidly. If i try to give it more gas it back fires on me. I will have to pull off the hwy and it will go about 10-20mph. If i shut the truck off and turn it back on it will run fine again.
Ive had a lot of work done to it fuel pump, water pump, fan clutch, alternator, plug wires, tie rods, had the intake manifold gasket replaced, along with replacing a bunch of hoses. I sprayed around on it looking for a vacuum leak but couldn't find anything and unfortunately this truck still runs OBD 1. I really dont want to sink a ton more of money into this truck. Any ideas?
make sure the catalytic converter isn't plugged up
I was recommended that by a couple people. The thing is rusted on there good though. Would there be any consequences to just cutting it off and straight piping it as far as sensors or the computer is concerned? Or do i need to replace it? My truck is emissions exempt in the state i live in.
emissions equipment is mandated by federal law
I meant its emissions exempt as far as paper work goes, i dont have to have it tested every year. I need the truck running temporarily. Would there be any mechanical issues to cutting it off on this specific vehicle?
Probably not on an OBD1 vehicle, there is no monitoring for operation of the catalyst.
Thanks. Looking further in to the catalytic converter potentially being the problem i found out about the EGR valve from one of scottys videos. Im going to take a shot at cleaning that up before i cut the cat off. Will post results.
Have you considered replacing your fuel filter? Has it ever been replaced?
First thing i did when the issue happened. It was a nightmare to get off, previous owner had it changed but they installed it way too tight (screw on fuel filter) and it took some serious effort to get it off. Problem still occurring though.