I have a 1996 F-250 super cab with the 351 engine with 123K miles. about 1 year ago I started to notice a loss in power. about 9 months ago my fuel milage dropped 4 to 5 miles putting me at 9 or 10 miles a gallon. I replaced the fuel pressure regulator because it had gone bad according to a good friend who has his own shop (he tested it and found it to be bad). My father inlaw said that he thought that by removing the cat converter i would gain my power back so I gutted the cat. I did not get any gain in milage or power. now several months later I am at a loss and so is everybody else. At low RPM the engine bucks and jumps at high RPM the engine bucks and jumps. In 5th gear (standard transmission) it bucks going down the interstate. No power what so ever. It back fires something fierce every once in a while. I use the truck as my main transportation to from work (not far) and I hall a goose neck live stock trailer once in a while. I'm scaried to hall the trailer now. I have checked the timing by turning the crank and watching the distributor. I get about 1/2 an inch of movement before the distributor moves. I maybe able to answer other questions if needed to help with a solution. The truck does burn oil, but it has done this for about four years and gets worse. I can see blue smoke when parked and running. I have inspected wires and such. I see nothing that would regulate and replacement.

 

I just bought a '95 F-150 with the same motor. On the ride home it felt gutless except when I floored it, pinged like crazy going up hills, bucked (I thought the torque converter might be bad, it was that bad), and even backfired good and strong back into the airbox when I revved it a little cold. It even wanted to overheat a little going up hills and would start pinging worse as the temp gauge went up.

I got a code for EGR valve not opening and one for fuel pump circuit problem. I put a new EGR valve and sensor on last night and it's running like a watch. Plenty of power, no bucking, no pinging, temperature's good, no backfiring. It was running really lean because the computer was calculating for some exhaust to be going in but apparently it wasn't.

Now, not saying for sure that's what your problem is but it is definitely one possibility. Do you get pinging going up hills at part throttle?

What is your fuel pressure at the fuel rail at idle, and also at idle with the FPR vacuum hose disconnected? I am getting 30psi and 40psi, I think it's a little low, I'd like to see more like 40 and 50.

You should get your codes read, even if the CHECK ENGINE light is not on it might have codes set that would tell you at least where to start.