Ive Got A 1991 4X4 4.0 5-Speed That Loses Speed Goin Up Hill On The Highway Empty, How Can I Get It To Maintain Power?

[Whoamidevine]

the truck is fine with everything else but just can"t maintain even 55 with the pedal to the floor in 5th

[coyote kid]

clean throttle body mabey your gearing is to high

[AeroNautical]

Wait a minute, up hill in fifth? Down shift to fourth, fifth is really just a cruising gear.

[coyote kid]

:agree:

[Echostrike]

Mine does the same thing. But I have yet to clean the engine at all. Interested in responses.

[jimoshel]

1st; Tune engine

2nd; Downshift.

 My DD is a '87 with 2.5 and AX4. Does 80-85 on level road and takes a steep hill to drop it to 65mph.

[Dirteatr717]

In my 89 with 4.0 ax15 with 33s and 3.07s I can get it to gain speed uphill in 4th if you use the skinny pedal BEFORE the hill and keep the rpms above 2200... Downshift and use your right foot :thumbsup:

[HOrnbrod]

What's your mileage and do you have the original catalytic converter?