I know I am beating a dead horse here. But my truck has 235K miles one it. It really is lacking in power. Is it just the outrageous number of mile or could it be something else.

Thangs done.

fuel pump
fuel filter
all of the COP's
airfilter
DPFE
new transmision
torq converter
plugs
maf
all new o2's

I am sure i am forgetting something.


Thanks
1999 F-250 4X4 Auto long bed 235K miles

 

Question is by what standard are you using to make the assessment of no power.
How can we/you tell?
Good luck.

 

That's a great question. It feels like I have a 4 cylendar that's missing two spark plugs

 

That description is still very subjective and very extreme.
Are you saying the engine can hardly move the truck (5000 lbs +\-) on the level?
This is what you would have with a v6 with several cylinders out.
Now lets get real!.
Any engine with that much power loss will have signs pointing to a fault.
If cylinders 'are' missing you WILL have cylinder fault codes set in PCM memory..
It's built into the engine control system and is not possible to 'not' show up as fault codes.
I still cannot get a feel for what your trying to say.
.
What you need to do:
1. Are there any codes set? If yes,what are they by code number?
2. Does the engine start normal?
3. Does it come up to normal; operating temperature?
4. How well will it move the truck up shifting through the gears?
We need to get a baseline of understanding and not just some foolish comparison because that does not help.
.
Once a direction is found, we work to find out what the problem is.
That is not done by just replacing parts.
A Scanner then can be used to look at stored and live data to further point to the cause and even be used to recheck that proper repairs have restored the data to normal readings.
I hope you understand the logic and not get upset with the reply trying to get you to address your issues in a more proper way.
.
Imagine if your doctor replaced your Arm because the Fingers on that Arm could not hold a pencil instead of finding out why the Finger don't work well.
For us humans there are no stores to get new parts from so we have to work with what we have.
Good luck.