No cajones?

[Red beast]

Ive had my ranger for about 6 months now. It a 95 xlt 4x4 5spd with a 4.0. It doesnt seem to have the power it should. It has 250000 on it but most everything has been replaced or rebuilt. At least thats what i was told when i bought it. It runs great and ive had zero problems with it. It has 31 inch tires but otherwise it is mostly stock. I can remember my friends and my brothers rangers being alot faster. Mine is slow.... Acceleration is a joke. Up hill is a joke as well. It seems to make its power between 2500 and 3000 rpm. I shift at 3000 just to be nice to it. It is my daily driver so i try not to ride it too hard. Especially with the heat lately. Is there something i should try or is my truck just tired. Are these trucks just this slow? What can i try to get my power back from it? No cel runs great. Idles perfect. Just looking for opinions. Thanks

 

[GentleRF]

One thing you didn't say was what the rear axle ratio was. It's kind of important to know since it will affect what size tire will work the best. Depending on what RPMs the engine is running at for a given speed will determine what your fuel economy will be. For example: my '86 ranger has a 3.45 set of rear gears. The "sweet spot" for it is about 2500 RPMs at 60 MPH. With 26 inch tires, I got about 24 MPG. Different engines will have different place for the sweet spot of torque an horsepower. If I were to choose to run 31's, I'd have to change the gears to either 3.73 or 4.10. Sheer economics would force me to keep the setup I have despite knowing where I can get a later model 7.5 with 3.73's for $150.00.

 

[RonD]

I would test the compression just to see what was "rebuilt".

Cold engine is fine,
remove all spark plugs
prop open throttle plate, or put something on gas pedal
put PSI meter in one cylinder
turn over engine until you hear 4 to 5 compression strokes
Write down the PSI for each cylinder, 150-180psi should be what you see

If it's lower repeat test but add a table spoon of oil(like 10w-30) to each cylinder before testing it.
Write down the PSI for each
This Wet Test tells you the condition of the rings in each cylinder, but doesn't tell you anything unless you have the Dry test results first.

Low compression makes for low power.

The computer(PCM) has no way to monitor the fuel pressure, it expects 30-35psi pressure in the fuel rail, it opens the injectors for a specific length of time based on this pressure.
If fuel filter, fuel pump or Fuel Pressure regulator(FPR) is reducing the fuel pressure then you could get lower power under load.
Fuel filters are $10 and a good general maintenance item to change.
You can usually borrow or rent fuel pressure gauge from auto parts stores.

 

[Red beast]

The gear ratio i believe is 3.55. Its a 4x4 so i wont be doing a regear any time soon. It just isnt in the budget. The engine wasnt rebuilt from what i know. The previous owner did have the trans rebuilt and put a new clutch and such in it. The clutch does feel weird to me though. Maybe because its new...er. The engine runs great, no getting hot, idle is perfect and has zero problems. The power loss doesnt feel like gears or the enigne lagging. Its kind of hard to explain. It almost feels like when an automatic transmission is going out; Revs up but doesnt go anywhere. The person i bought it from was a spoiled kid who had dad throw alot of money at it. He sold it to buy a bigger truck that could tow a boat. It has a magna flow cat and a flowmaster on it. All stainless piping. Dad didnt spare any dollars. I know this truck should be faster than it is. Its the whole reason i wanted the 4.0 ranger. I apprecite any feedback or help... This kinda has me stumped. The truck is in EXCELLENT condition so i cant figure what the power loss is from. To give an idea... I got my ass kicked going up hill by my friends scion xb. It was embarassing. Help me out guys. I plan on keeping this truck for a very long time.