Hi!
Okay, I bought a 1992 F250 about three days ago. When I test drove it, I did note that at 60-65 I gunned the gas pedal to see the reaction. The truck didn't pick up speed much but the tone of the engine became a gurgle.
This truck has 44K miles on it and a new motor (not a rebuild) 351W with less than 8K miles on it.
So, being a naive girl perhaps, I assumed that (and still am assuming) that this is a simple problem.
After driving about 80 miles I began to feel the truck surging upon acceleration. By the time I got home (I did not think I would make the last few miles) the truck would not go over 25 mph and sputtered. I pulled over a few times and put it into neutral then blasted it with the gas pedal (in desperation and frustration). The motor would sputter than open with a sound similar to something spraying within the engine compartment.
This truck did sit for a while. I had the fuel filter changed the next day and the mechanic said it was very, very dirty. I picked it up and it drove, but not great. Within 15-20 minutes the problem returned. It creeped home at 25 mph.
So, today, in the freezing snow, I pulled off the exhaust from the muffler back to expose the tailend of the cat. I busted out the front portion of brick and the rear portion was non-existent. The truck seemed to breath better and run better, but after a 15-20 drive the same problem returned.
I just put some injector cleanser in it (Chevron Techtron) and cleaned the distributor points and rotor (they were rusty and had a lot of carbon on them). The truck seems to drive a little better, but there is still something going on. The idle fluctuates up and down and it doesn't want to accelerate very quickly at all.
Seems like I spent my last dime buying this truck and am looking now for resources to fix it myself. I read up on the sensor tests and that looks to be a tricky find.
Anybody with a suggestion? I just find it interesting that it will drive okay (not great) when cold, but as it warms up it quickly deteriorates.
NOTE: Just drove it again tonight, drove pretty good, but after 15 minutes went to crap. Seems to respond better with a super light foot on gas pedal. Too much gas and it gluts up...Any genious ideas or is this beyond anyone's scope here??
Thanks!

 

get a fuel pressure test guage and screw it into the shrader valve on the fuel rail and see what its doing that an easy test and should eliminate some things. 20 dollar test kit .

 

where is the shrader valve? and fuel rail - sorry not familiar with those...

 

the fuel rail is what holds the injectors its between the upper and lower intake on top of motor. the shrader valve looks like a tires valve stem its a test port located firectly off off the driver side of the fuel rail. it may or may not have a cap on it.

 

Is the exhaust blowing black smoke after it warms up?

 

Sounds like dirty injectors

 

to Subford: No black smoke...

It is snowing like a sonofagun today. I think I can get the truck to the auto supply store and back - Get to try out the 4wd!

 

I am going to get new plugs and wires too...There go my nice nails!
Actually, the guy that sold me the truck said he will get it working if I can "get it to his place"...Tempting, but not in this snow

 

Go with the new plugs and wires anyway, they will pay for themselves over time in reduced fuel consumption. Have you got a check engine light on? Did you notice if it ever did come on? The first thing that came to mind reading your post was plugged exhaust. However I then got to the part where you gutted the cat. Are you confident you now have good exhaust gas flow? Before you spend too much time and money on it you may want to take up the offer from the seller to fix it. Just my thoughts. Good luck with it.

 

to Lazy K:

I have considered clogged exhaust, however when I did gut the cat I only had to gut the upper portion. The portion nearer to the muffler was already missing. So, could it possibly be inside the muffler? Would this cause any back pressure? There is no rattling coming from the exhaust.

The seller said that everything on the truck motor is new, however when a vehicle sits for a long period of time, say a year, will the plugs and such go bad? Obviously, the rotor and cap looked sub par...