My wife and I recently visited the Atacama desert In Chile and took the opportunity to rent an overland vehicle complete with an RTT. The Chinese made “Wingle 6”was all good until we reached 16,000’ attempting to make the pass. Eventually the truck lost all power and we were forced to turn around only .25 miles from the saddle! It was heartbreaking!
We’re considering making another attempt but this time with America on our side. I’m considering shipping my 2000 jeep Cherokee and trying again. What’s the highest someone has taken their Cherokee?

 

Power reduces with altitude since there is less oxygen to burn the fuel (pilots use the rule of thumb 3% power loss per 1,000 feet increase in altitude), but it shouldn't be like a switch. It should fade slowly and evenly as you go up. I would describe failing suddenly to be a broken system. My Subaru was down to nearly half power at the top of Pike's Peak 14,200 ft, but it had no trouble doing things, still pulled reasonably well, and idled smooth. I could still drive irresponsibly fast at 14,000, so you should have been fine at 16,000. Cooling can degrade a tiny bit as well, but I wasn't running any hotter than expected for 30 minutes of full throttle. If I wasn't pushing so hard I don't think it would have been noticeable.

So, I don't know what the max elevation is that someone has taken their XJ to, but I bet there are lots that have been to 14,200. That is the highest road I know of in the 48 contiguous US states. If we can get some Andean people to answer they have lots of high altitude roads. I don't expect there are a lot of XJs in Nepal.

 

Good points. The only thing I can think of is the Cherokee doesn't use a MAF sensor and relies on MAP instead, I wonder if it would adjust mixture to low density air as well.

 

Now that you mention it, I've heard some early OBD II computers with MAP/speed density don't always continuously adjust for sliding ambient air pressure, but only check it once at startup. Perhaps that plays a role in the OP's situation. My Subaru is MAF only so ambient pressure doesn't really matter, it just reads grams/second of air flow. Also, I started the engine near the base of Pike's, so the relative elevation change may not have been that much. It's pretty easy in the Andes to start the engine at sea level and in a couple hours be at 16,000 without ever shutting down. That might freak out an ECU that only checks at startup and cause it to 'fail'. One that old would also probably not be smart enough to set a code for implausible MAP vs. TPS. I expect it would run a lot better if it was using the primitive method and it stalled and was restarted.

 

Was the Wingle fuel injected or carbureted?

 

So, the Wingle 6 was a modern fuel injected vehicle. The loss of power was gradual as we made our way up through the volcanic pass. The road was not steep, maybe 5 or 7% grade, but it was a long gravel road. We were running low
on power when we came upon snow drifts that we’re crossing our path. The drifts would have been no match for my jeep at home I thought so I threw the Wingle in to 4 wheel high… I attempted to get a running start to plow through the first one… with the gas fully depressed the vehicle made no attempt to give me the extra momentum I was looking for. Instead the front two tires hit the first drift at less than 5 mph. Of course with this weak *** approach the front two Wingle tires simply lodged themselves firmly into the drift. Again, even with the throttle fully depressed, the little engine just didn’t have the power required to send to all 4 wheels. None of the wheels would spin.. at this there was no fighting it so we putt it in reverse and rolled around into the downhill position. It was very demoralizing. My only thought was “damn this Chinese made POS! If I only had my Cherokee!”

 

Wingle displacement?

 

The JTEC will perform a baro correction at key on.