If you have any propane or carb & choke cleaner try enriching the mixture and see what happens. The computer should produce some kind of code if it is running too lean or too rich.
Have you checked the fuel for contamination like lots of water. Take some out of the line and try to lite it with a match away from everything of course. It should ignite instantly , if not check further for what is really in the tank.
I will try to offer suggestions, but it seems we need to start from scratch here.
There are certain things the computer will not control and fuel quality is one of them.

 

leave number one spark plug wire in that position and and remove all others and relocate them in the counter clockwise order and see if that doesn't do the trick and that's another thing that the pcm can't control

 

I have a 94 F-150 with a 4.9 in it as well and it turns clockwise as well so please disregard what I said before I was wrong when I said to do that and I am sorry for it.

 

If nothing helps so far, consider trying this . Remove one plug wire and place it so you can see the spark when it is idling, then raise the engine speed and see what the spark does if it stays strong that would eliminate spark quality. If it dies just before the engine dies you need to find out why. Were you able to see what result you would get if you added fuel to the intake as suggested earlier?

 

I had similar issue and when I changed o2 sensor did you reset computer? If I remeber you turn key from from all the way counterclockwise to the power on clockwise 5 times and the dash lites will blink then start the truck and run at 1800 rpms for 1 minute then at 3000 rpms for 1 minute and then 1200 rpms for 1 minute then cut off and restart normally. It recalibrates the computer for the air to exhaust mixture. Call a shop and ask for the specifics. I was surprised at how simple. A few years later my computer went and cost about 100$ for a replacement but you must match numbers exact. By the way I had 247000 miles and still strong as new, 3 transmissions and two fuel pumps alt, starter the normal wear and tear, I replaced plugs, dist, wires every 30000, oil 5 to 7000. Wish I still had that beast. Best of luck.

 

I am beginning the think that a comp. test would be in order now. that could explain a few things like the rough idle and no power issues

 

So I took it to be evaulated and I was told it was the cat so I had it replaced. It did not fix the problem.

 

If I recall that converter is quite expensive. Is there some reason you don't want to try the earlier suggestions?

 

Whyte,
What if it isn't a mixture problem as you suspect?
That engine should have a crankshaft sensor that provides the info for spark to take place. The PCM controls the spark timing, but it gets it's info from the crank sensor.
If that info is intermittent so will be the spark and power. Might pay to check the output and connections and wiring coming from that sensor.

 

Hanky, in 96 they still had the dist. on those engines therefore no crankshaft sensor was needed. my 94 doesn't have one and the only time they put those on the engines is when they use coil packs there should be a control box of some sort mounted on the inner fender on the drivers side and that thing could have went bad but if it did it wouldn't start at all nor would it backfire or buck let alone run any at all. so I'm thinking it could have jumped time or the timing chain is so loose that it could have too much slack in that the pcm can't make up its mind or make the adjustment to make it run smooth