88 ranger 2.9.. runs fine when you first start it up in the morning.. but around 15 mintues of running it loses power, barely can hold itself in 5th gear.. its hard to get it over 2000 rpm's.. it also will very lightly sounds like its backfiring through the top of the motor.. when you floor it going down the road it will just will bog down..
the motor has a bad ticking to it also, but alot of the 2.9's do

It sounds to me like you may have a plugged up exhaust. I would disconnect the exhaust at the flange in front of the catalytic convertors and drive it. If it runs fine, chances are one of the cats are plugged. If no change, my next guess would be a fuel pressure concern. Maybe the fuel pump is tired, maybe fuel filter is plugged, but I would still check the exhaust first because I've had it happen to me. Hope this helps.

it has 2 catalytic converters on it.. the front one gets hotter than the back one, which they are right next to each other.. it has 3 fuel filters on it

also i just had it idling for about 25 minutes and it ran fine.. so its only acting up when the motor is under a load, like just actually driving it

also i just had it idling for about 25 minutes and it ran fine.. so its only acting up when the motor is under a load, like just actually driving it
Check spark plugs and wiring. Do the water test on spark plug wires. Spray a little water on them with a water bottle see if it arcs over.
Sounds more like an ignition problem to me how long since you've tuned it up?

the plugs, plug wires, distributor cap, rotor, and the ingintion module on the back of the distributor are all about 2 or 3 months old

the plugs, plug wires, distributor cap, rotor, and the ingintion module on the back of the distributor are all about 2 or 3 months old
Just because they're fairly new doesn't mean they can't be defective, especially plugs.
Could also be incorect plugs, just acts up under load, and when hot, sounds like detonation(ticking).

ok ill run the numbers on the plugs and see if they are the right ones.. and check to see about detonation when i take them out

I just recently started to have the same problems with my 86 Ranger. The exact same thing as you described. Have you figured out the cause of it yet?

it was injector problems.. they needed to be all taken out and cleaned.. and the fuel pressure regulator was also bad.

Thanks for the conclusion of your problem. I just bought this truck this last summer and the guy told me that he just replaced the fuel pressure regulator. Maybe it went bad again.