Prepping XJ for high altitude wheelin

[jstggs]

What steps should be taken to prep an 89 XJ 4.0, 5spd, NP231 for wheeling in altitudes of arround 13k feet. I'm headed out to Silverton CO and I'm planning on hitting Imogene pass and a few other trails.

Thanks guys

[Kuasimodem]

Run the tank down and purchase a full tank of fuel locally. At higher altitudes they use a different blend of fuel to help control knocking and pinging.

The computer will do the rest in adjusting the engine:D

[wilcharl]

has anyone messed with the high altitude jumper on the renix?

[langer1]

has anyone messed with the high altitude jumper on the renix?
I didn't know there was one. There is a High altitude CPS.

[90xj06]

i remember hearing about one but i though it was only on a tj. is there one on an xj. if so where?

[old_man]

No jumper.

Make sure you have a good 16lb radiator cap and that your serp belt is good. Check your air filter as well.

[Shrubs]

Yeah, I'd be more worried about your cooling system than anything else. Make sure you also follow the manufacturer's req on octane rating. They sell 85 out here and people have problems with it. Stick with 87 or higher. Oh yeah, and have a blast. The Silverton area may be one of the coolest places in North America.

[BigG]

I used to live in Crested Butte, CO. My XJ and my dad's Tj have never had problems using the regualr 85 unleaded. At the high altitude the lower octane works as well as the higher octane at lower atitudes. As was mentioned above, Get a full tank of the local stuff on your way in to balance the fuel mixture. The big thing though is to fill up with premium on your way out to balance your octane back up.