LX450 has NO Power going up the Grapevine

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Sep 24, 2006
Hello and help.

I have a '97LX450 (with about 110k miles) which is not being used regularly because of the present gas price situation. BTW, the HG has been replaced sometime ago.

Anyway, I used the truck a couple of weeks ago to go to LA from SF. The drive from SF up to the foot of the Grapevine was uneventful. A little slower than what I am used to with it but at that time, no big deal. When I started going up the grapevine, I started to notice the truck loosing power. As I went higher, the more it got worse... and to top it all, it started to heat up (even with the aircon off). The power got to be so bad that I had to "crawl" using the truck lanes going up.

When I got to the low lands, it started to get more power...similar to the power I had from SF to the foot of the Grapevine.

Any ideas on why this happened?

I was reading on some previous posts and somebody mentioned the O2 sensor. Is this possible?
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Curious to hear if there is a resolution because I have the same exact vehicle with the same exact issue and I just figured it was normal. Hoping its not and there is a simple fix for it.
Do you know what gear the tranny was in...maybe stuck in overdrive?

No. I wasn't on OD. I was in "D" first and then tried down going to lower gears to no avail.

NLXTACY: It definitely is not normal because I have gone through the Grapevine with full aircon on the speed lane with the same truck before.

BRIAN: Used to live in Bellevue, WA and have gone through Siskiyou several times without any problems.
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Ugh, dammit. Now something else to look for. And no, never in O/D going up hill. Although...my PWR button hasn't worked since day one.
from reading stuff here it seems like on a fairly steep climb (6% say) it would not be surprising that an FZJ would drag itself up at only around 45-50 mph with some encouragement, and that downshifting to 2nd may not be out of the question to make that happen.
A 3FE... well.... :D Feed those squirrels more...! :)
Something's wrong.

I drove I-70 up over the Eisenhower in the fast lane w/ my 93- loaded with a weeks worth of camping gear, two bikes and two blokes. I had to put my foot in it's ass.... but still......
Agree something's wrong. I've driven that route dozens of times.

Check to be sure all your warning lights illuminate when you turn the key to 'on', and then go off after a few seconds. I'm particularly interested in the check engine light and the hot transmission warning light. Check your owner's manual to see where these lights are so you will know if they don't light - there's a nice diagram showing every warning light on your dash.

I suspect you've got a check engine light, but the bulb's burned out so you're not being informed. If that's not it, you may have a vaccum line off or something improperly reinstalled from the head gasket work. Timing could be off, a tear in the bellows section of the rubber intake tube, or all of the above.

Definitely not right though - I'm thinking timing due to the heating up.
For me yes, not sure about MALMON.
I have made that trip many times. Stock tires 65 mph in drive no problem.

Fully loaded with 35's and 4:56 gears 2nd gear and 55 I will hit 195 water temp near the top when it is 90 outside.
Stock size tires still?


Yes, I still have stock tires.

No CEL or other trouble lights go on and... all my light indicators work.

There may be a slight delay in the timing (just for the sake of argument) but then, if I have a delay of say 1* or 2* (say I'm at 5* BTDC), that delay should not affect the drive up that much.
old, beat throttle cable out of adjustment?
check the air filter for clogs... cracked and leaking air intake...

just some ideas, good luck
The southbound climb is steeper, but it does indeed sound like you've got issues. Several times over the grapevine at normal speeds both as a stock LC and as she's now configured (see sig line).

Now this coming weekend with a 4000 lb trailer being towed will be a situation similar to yours and at about 8mpg if I'm lucky. :crybaby: Did just replace two shot O2 sensors this past weekend so maybe 8.5mpg!
Forgot to mention that I do have a Kaymar rear bumper with a tire carrier and an ARB winch ready bumper in front but I've had these for years and I never had a power problem like this.

I'm afraid that if I bring the truck to a stealership, I might end up poorer with not much improvement to show for it. The good thing is that the LX is not a DD so I have time to work on your ideas.

So guys, please keep the ideas and suggestions coming.
Ugh ok, then I guess I do have serious issues then, I don't have any armor and stock tires.

Sad panda.

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