High Elevation Stutter???

hansken_yo · Post by **hansken_yo** » Mon Jan 15, 2007 9:25 pm

Alright, so I’m completely baffled on this one and am wondering if anyone else has had similar experiences.

Car info: ’04 SXT, MT w/ CAI and Exhaust. (suspension doesn’t matter here)

Since I’ve installed the CAI and the exhaust I now have as what I can best describe to be a stutter when I engage first gear AT high elevations. Sometimes is small, sometimes its big, sometimes it is non existent, but what I do know is that it doesn’t occur somewhere below 2000ft elevation.
Now I’ve had my clutch, and transmission checked, and that is all good (oh and I’m very familiar with how to drive stick as well) so I think it is down to the air quality. I’ve disconnected the ECU and the Battery to get the computer to “re-learn” the environment, but to no avail.

Has anyone experienced this or have any ideas as to what is going on and / or what I can do to get this annoying stutter to stop (besides going back to sea-level)?

Thanks yo.

Marthby · Post by **Marthby** » Mon Jan 15, 2007 10:23 pm

Well it is normal for an n/a car to stutter at high elevations due to the decrease in oxygen levels. My car seems less "peppy" at higher elevations but it doesn't stutter. Could it be an MTX thing (I have an ATX)? Kinda doubt it...

kc2005ptgt · Post by **kc2005ptgt** » Tue Jan 16, 2007 6:23 pm

Yeah, I would think it is just because of higher elevation, not as good air quality, but hey, I really thought that only mattered above 5k ft mark??? I only live in 800-1000ft, so I duuno.

hansken_yo · Post by **hansken_yo** » Wed Jan 17, 2007 12:14 am

It started at about the 3.5k mark for me, and reno is at about the 5k mark... so yeah... I was just hoping there was something that could be done about it.

OB · Post by OB » Wed Jan 17, 2007 1:55 am

very normal, but the computer should be able to compensate for the change in atmo pressure. it can only do so much though. I dont think u have a thing to worry about. If everything is in good order, there wouldnt be anything u could do anyway

03blackrt · Post by **03blackrt** » Wed Jan 17, 2007 2:14 am

Just to clarify, there is not less oxygen the higher you go; there is not worse "quality" air the higher you go. In the homosphere (The homosphere is the region of Earth's atmosphere which extends from the Earth's surface to an altitude of about 80 km.) there will always be 21% oxygen by volume; the air "quality" will remain the same. It's just that air pressure (and therefore density) decreases the higher up you go. It’s the decrease in density that kills the performance, not a decrease in "quality".

Just a nerdy pet peeve of mine...

hansken_yo · Post by **hansken_yo** » Wed Jan 17, 2007 11:51 am

I was aware of the power loss due to the lower air pressure, which was part of the reason I went to these minor additions to get some back. It got me enough power to get around here without having drive at 7k rpms all the time (well maybe not that much, but you get the point) and resulted with a stutter. Sucks that it appears nothing can be done, but thanks for the info.

sullygully · Post by **sullygully** » Wed Jan 17, 2007 1:18 pm

Here you go.

http://www.ertyu.org/steven_nikkel/neon ... 019-00.pdf

Print that out, and take it to your dealer and tell them that you want them to flash your pcm with that info, because you are experiencing hesitation when accelerating at high altitudes.

I haven't yet done this, but i plan to this summer, since i live above 5000ft.

However, if you don't drive on a regular basis above 5000ft, that i would not recommend you getting this done

hansken_yo · Post by **hansken_yo** » Wed Jan 17, 2007 3:51 pm

yeah... I'll be up here for another 5 months then its back to Seattle in mid May. And Dude... that description is exactly what is occuring in my car. Awesome!!! thanks yo