Struggling on the hills

[hickmanm071]

So let me jump right in; She is a beautiful 1984 CJ7 with the AMC 258 i6 / 4.2l , sure she has seen better days but there is a lot of life left in her.

The issue I could use some leads on is this, once I hit the trail and need to climb I am constantly revving the motor to try and get enough power. Highway driving is fine, and around town she does great. Even in 4 Low when I should be able to just put her in gear and walk along side, I am revving the motor just to get over some small whoops and hills.

In 2013 I took the factory carb off and replaced it with a Weber, because the electronic switch in the factory one was faulty. I think this is when the problem started, but it feels like it has gotten worse the last two summers I tried to head out. I am in Colorado, live around 6000 ft and one suggestion I got this week was that the new carb probably doesn't have jets for high altitude. The other suggesting I got was a vacuum leak (and in an 84 that has been though 4 other owners, the vacuum is sloppy).

Do either of these seem probably and does anyone have any suggestions on which I should try first?

Thank you all!

 

[Lumpy Grits]

:ww:

What size tires are you run'n?
What's your R&P ratio?
What tranny?

LG

 

[hickmanm071]

I am going to assume that the Transmission is Borg-Warner T-5 , since that was stock on the 5 speed 84's. The tires are 32X10.50R15. And I don't know the ring and pinion ratio, but I think it is 3.73. Again I am going with what stock based on the history I know from previous owners.

 

[Lumpy Grits]

More like 3:31 R&P. Not good with 32's, at 6K' ASL.
The OEM, R&P is stamped to the right of the rear diff cover.
https://www.jeeptech.com/axle/amc20.html

Put a wrench to every manifold nut you have. Especially the intake manifold.
Check the carbs mounting nuts also.


LG

 

[hickmanm071]

Thank you, I will do that

 

[mtnwhlr]

I have the same Jeep and have done the team rush upgrade and now that you are no longer running the stock carb you need to do the tricked ignition to take the computer out if it because it is messing with your timing.

 

[El Jeep o]

Lumpy, I watched a video about checking the gear ratio by lifting the back end, marking the tire and the drive shaft. I did this and rotated the tire one full turn and only got just under 1 1/2 turns. That would give me about a 1.4 gear ratio, is that even possible? I did it three times to be sure I was seeing things right.

My Jeep had 3:31 gears and with 33" tires and would not go any where in 4 HI. REALLY BOGGED DOWN. 4 low worked kinda ok. FYI

 

[hole]

If you are lucky you have 3:31's, but probably 2:73's. I still have 2:73's with 32's and mine is not a big fan of hills either.

 

[Lumpy Grits]

Hey OP-
Any new information to share with us?
LG