No Power

[milomilo]

I have a 1989 2.9, 4X4 that has very low power in 5th gear and won't maintain 65 mph on even small inclines. I have had no check engine codes. I have replaced the spark plugs, air filter & fuel filter. The cats are not plugged and I have a new muffler. Timing is set a 10. Is there any type of engine timming change that occurs when shifting into 5th gear?

 

[IMenriched]

Are you trying to run extra large tires??

 

[89DangerRanger]

im running 30's and i have the same prob, the engine is just underpowered it cant handle them

 

[fastford04]

im runnin 31's trust me 31's 3.45 gears an a 2.9 aint that great of a match up!!lol haha

 

[holyford86]

i will vouch for no power with 3.45 gears and 31 inch tires, I run 4.10 gears now because of this, can't go over 65 for any length of time because the motor revs too high for my liking but I never go that fast anyway, at 50-55 mph the motor is in its happy place it seems, right at 2500 rpm at 55mph.

 

[ranger]

might want to try changing your rear end gears i dont really have a problem cuz i dont use 5th that much with 31's and 3.73's i drive in 4th most of the time never really use 5th so you could try changing to 4.56 gears that is what im planing on doing

 

[milomilo]

It has an 86 for axle on the door stciker. What gearing does that give me? It also a lifter clicking and the previous owner said he had the lifters and pushrods replaced but the clicking didn't go away. What is the adjustment for the lifters after zero lash? Is it a quarter turn more like Chev V8's?

 

[milomilo]

The tires are 235 75 R15's.

 

[CraigK]

You may have done this already, but didn't mention it . . .

I put in new plugs a few weeks ago and noticed no difference in my '87 B2 (AT, 3.73 axle, 235/15 tires). Then this week I replaced the old distributor cap and rotor with new "premium" units. (The "premium" units have bronze posts in the cap instead of aluminum.) I was surprised at the heavy amount of corrosion buildup on the aluminum posts inside my old cap. The result was an instant increase in power, and a smoother running motor.

That said, it's still woefully underpowered.

CraigRK