Dudes. I drove 18 hrs yesterday to get o Denver. Now my truck is DOG slow

[Riders of Lohan]

Hey guys.

Drov from Chicago to Denver by myself yesterday. What a ****ing mistake

I think I underestimated the toll the mountain pass would have on performance.once I got up to 9,10,11k feet, this thing was such a pig. I couldn't do any more than 60 even downhill.

Overdrive was off - but I had to drive this thing HARD To still be slower than everyone else.

I think I will swing by a shop but anyone have any tips or experienced the same kinda thing?

Driving to breckemrodge area at 3 a, down the pass is the least fun I have ever had in a vehicle.

 

[Riders of Lohan]

Typing from ipad :bravo: sorry for spelling errors

 

[mtnwkr]

Maybe reset your ECU so it can reprogram itself for the lack of o2 at that elevation?

 

[calimobber]

I drove my 4runner pulling a 6x10 trailer full of stuff from LA through chicago up to the UP by myself then back 6 months later, so I know your pain.

I didnt feel it was that bad.I def was in the slow lane in the rockies doing 1st gear but outside the the rockies I can only do 55mph with the trailer.

But im used to mountain passes so I know how they put a stop to power

 

[Riders of Lohan]

Maybe reset your ECU so it can reprogram itself for the lack of o2 at that elevation?

My mechanic said that wouldn't really help but I might clean the MAF and reset ecu

 

[Stiles97]

ecu is constantly adjusting air fuel mix so yes a 'reset' is not going to do anything. air filter clean?
any vehicle is going to feel down on power at that altitude. It is gradual until coming into Denver but then will become very evident as you get into mountains.

 

[bama16]

i've always felt that it moved pretty good up here...but i've never driven it at a lower elevation either.

 

[OffRoadGuy]

Might be the gas. Don't pour 85 octane gas. My rig didn't like it at all, even on the gradual peeks the big rigs was passing me up. min of 87 octane.

 

[shootmymime]

My mechanic said that wouldn't really help but I might clean the MAF and reset ecu

reset the ECu by pulling the EFI fuse under the hood fuse block by the batt.

keep it out for at least 60 seconds and it will clear any CEL as well as the learned driving conditions. best thing you can do for it right now.

 

[white_n_slow]

Both my runners were 5-speeds and they could do 65-70 right up and through the tunnel both directions. I did have to leave it in 3rd gear to maintain speed on the steeper bits.

I would shut OD off and actually drop it into 2nd for the particularly taxing portions of the drive (Georgetown Hill, Floyd Hill, EB up to the tunnel). My understanding of toyota autos is that they actually do better temperature wise and wear wise to be left in a low gear at high RPM compared to switching back and forth between 2nd and 3rd as your foot dictates. When you get to the top of the hill, just put the shifter back in D.

There is no denying that once you get past Georgetown any naturally aspirated vehicle will feel like it's lost half it's horsepower. Even in a vehicle with plenty of power (my DD is an Acura with close to 300hp) you can still feel it. Just be glad you're not driving an 80 horsepower 22r mini truck

 

[Riders of Lohan]

Hmmmm, wonder if 2nd is the right gear for 59 mph? Will try some octane booster today and get higer grade when I'm on E

 

[jgue467]

42% power loss

... I underestimated the toll the mountain pass would have on performance.once I got up to 9,10,11k feet, this thing was such a pig. I couldn't do any more than 60 even downhill.

Dude - performance on any air breathing engine declines by at least 3% for every 1000ft of elevation. So on the rockies at around 14000, the engine has lost at least 42% of its power cuz of lack of air. Rocky Mountain way - couldn't get no higher! :cowboy:

 

[slides]

My friends live in evergreen and they run premium out there. They say the gas is pretty shitty, but with premium they avg 20mpg in their 3rd gen.

 

[Asaspades93]

I know the feeling, moved from ny to boulder in september, I have to hold it at 3500 to maintain 55 going up most hills hahah. I did put 87 in last fill up and I seem to be getting better mileage so far

 

[02SE]

Chicago is at just under 600 ft in elevation. So your 4Runner would be making approx. 1.7% less power than it could at Sea Level. Driving over the highway mountain passes in Colorado, such as on I-70 through the Eisenhower tunnel, which peaks at 11,158 ft, you would be down over 33% from what the engine could produce at Sea Level.

That's a dramatic loss of available power.

You don't need to pull a fuse or battery cable to 'reset' the ECU. The fuel injection system will continuously adjust to differences in air pressure, as you drive.

You are just experiencing the Effect that high altitude has on any naturally aspirated vehicle.

 

[T4R2014]

I would be running 93 octane. The octane-booster-in-a-bottle crap is not the same thing.

 

[mountain mike]

^^ Highest octane we have out here is 91. I have looked for 93 for years and have never found it.

 

[02SE]

The higher you go in elevation, the less Octane the engine needs. The Octane rating refers solely to the AKI (anti-knock index) of a particular gasoline.

That's why Regular (which is what a stock 3rd gen is designed to run on) is 87 r+m/2 Octane at lower elevations. While at high elevation, Regular is 85 r+m/2 Octane.

Less air pressure at high altitude, means less cylinder pressure in the combustion chamber. With less cylinder pressure, there is less chance of pre-ignition (knock).

If the engine isn't experiencing knock on Regular gasoline, Ie: the computer isn't sensing knock, and retarding the ignition timing in response to knock, using a gasoline with a higher Octane rating will do nothing for the engine. You will just be wasting your money on higher octane gas.

 

[hour]

I do that drive several times a year, I am also dog %#@! slow. Getting passed by semi trucks is no new thing for me on that stretch hah. Have never run anything but 85octane trying it though, worth a shot to do 89 or something.

Some days seem easier than others and I don't know why, maybe I'm more patient? Over sized tires, a bunch of weight up top, and weight on the nose definitely didn't help my cause. If you're going to be here for a while, become friends with the furthest right lane and get familiar with where people enter the highway or the lane ends

 

[KidVermicious]

Might be the gas. Don't pour 85 octane gas. My rig didn't like it at all, even on the gradual peeks the big rigs was passing me up. min of 87 octane.

You drive a 3rd gen, yes? You should know that your ECU is not smart enough to advance or retard timing based on the octane of your gas, the way some modern vehicles are. Putting 87 octane in the tank did not magically give you more power.

The one scenario where it might have helped is if you were knocking/pinging due to other issues and your knock sensor cut the timing. There, higher octane might have reduced the knocking enough to let your ECU restore the timing advance, but that'd be because your motor had issues, not because there's any more energy inherent in higher octane fuels.