I have owned my 1988 f250 351 4x4 for about six months. It was lacking power so I replaced the rotor, cap, plugs and wires as a first line of action. (I had to use 4wd in low range to haul a load of wood out on forest roads). The tune-up gave me a little more power but there is still a definate problem. From a stop when I press down hard on the accelerator the engine increases in rpm only marginally and there is very little power at the wheels. I have nearly as much power slowly pushing the throttle as I do when I floor it from a stop. At higher speeds it seems to react better. Any ideas of the culprit? Maybe injectors, tranny? I cleaned the k&n filter with no change in behavior.

Thanks in advance for the input

 

Auto or 5spd

 

Sorry for overlooking that. It is an automatic.

 

Clogged exhaust or fuel filter maybe.

 

is timing correct, plug wires on correctly, clogged cats?

 

How much could clogged cats hurt the performance of a 460?

 

it could stop it from running completly if clogged enough.

size of the engine makes no difference if it can't breath in and out.

 

how often do cats get clogged becuase i seem to have the same problem with lack of power sometimes?

 

very often.

use a vacuum gauge to check if they are clogged.

 

you can also unbolt the Y pipe from the manifold , it will be loud but you will notice improvement right away. I would also check codes www.fordfuelinjection.com will tell you how. what size tires are you running and what gears are in the truck. I imagine the tranny is a C6 correct? whats the fluid smell/look like and when was it serviced last?

 

i have the manual 4spd with the granny gear..also i hollowed out my cat about 20,000 mikes ago....and i just changed the tranny fluid (and i added some lucas) but still no difference... it doesnt really bog but it feels like something is holding it back as if i was towing something?

 

emergency brakes not releasing properly.

 

nope that was the first thing i checked

 

I will check the cat and did buy a fuel filter to replace the old one. The wires are all properly ordered and connected. Although I have not put a light to the timing issue. I appreciate the input. I am glad no one seems to think the tranny is an issue as that was the most expensive culprit. Again thank you for the suggestions.---btw no cel but will pull codes anyway.

 

i just remembered an old post that stated that the cooling fan clutch was causing something like what you are describing.