az_eaglescout_pilot

iTrader: (1)

I've taken a few road trips lately to different places and noticed that when i go up in elevation theres a significant power loss, like the computer is not adjusting the mixture correctly...i live at 2600 feet, and flagstaff is about 7000 feet. also just got back from LA and noticed some power gains and a higher idle down at sea level...what sensors should i check...when it cools down here in tucson i'll go outside and check codes to see if i missed it throwing one...on a side note my rebuilt 3.0 did excellent besides the above issue, started every time, averaged 16.5 MPG with 4 people and junk in the back running 75-85 mph, AC could use a charge lol...115 when we passed through Blythe.

anyways any help would be greatly appreciated, wanna get this thing running perfect before school kicks in so i can focus on classes...

EDIT: pulled code 41 which i believe has to do with the TPS sensor...guess i'll start by making sure its adjusted correctly, but i feel like that wouldnt be the main cause.

-Jordan

Jasper 83

Normally a naturally aspirated engine will lose power at substantially higher altitudes than at sea level because of the difference in atmospheric pressure. The air gets thin at 7000 feet and the drop in pressure means there is less air being pushed into the motor allowing you to burn less fuel. Sounds totally normal to me. The computer is keeping you from fouling your plugs up because it is adjusting but as far as making the same amount of power at 7000 compared to sea level. Not gonna happen without a turbo set up to wastegate all of its boost at sea level and adjust with altitude.

irab88

iTrader: (4)

yup. that's the reason behind turbo-normalized aircraft engines. they're turbo'd, but not for power. they have the same power at higher altitudes as they do at sea level

az_eaglescout_pilot

iTrader: (1)

ok so nothing is wrong with the mixture control at a higher elevation...but what would explain the lower elevation symptoms?

irab88

iTrader: (4)

shoot, you should know about altitude power loss (i just read your signature) ... i'm in aviation maintenance school and am an eagle, myself

anyway, you mean the high idle? not sure on that one, as i'm not familiar with the 3.nada. i'm sure someone else knows, though

TNRabbit

Your idle control doesn't adapt, so the denser air at lower altitude results in a higher idle. you'd need to adjust it manually (flathead screw built into the front of the throttle body as your looking at the engine from the radiator).

az_eaglescout_pilot

iTrader: (1)

its adjusted all the way out already, probably has to do with my tps being out of whack, but it sounds like everything is normal? cool!

irab88: eagle scout! and i havent flown in over a year due to money and time, im currently in school for mechanical and aerospace engineering so theres little time and money for other things...which means SAS is gonna have to wait till next summer...BOO

irab88

iTrader: (4)

idle control: screw in to lower idle, out to raise