[mysocal911]

Originally Posted by johnman001

Thanks for those replies. I think I may take the car out this weekend to see if my issue seems to be gone. I suspect it just might be. I have downloaded and archived most of the wayback machine as it pertains to the old info once available from FR Wilk (the944.com), but it is/was operational theory that seems to be lacking. For instance, was fuel delivery reduced at elevation, or was timing adjusted as well?

Also, I know that at full load (full throttle switch made), the O2 sensor input was supposed to be ignored. Not sure if this was also true with the altitude sensor or not, but in my experience, my car ran better at part throttle with the altitude correction sensor switch stuck closed, so I'm guessing that at lower throttle positions, the O2 was adjusting the mixture over-riding the altitude correction sensor.

I've never had my TPS apart, but I had assumed that it was a carbon track wiper instead of a micro switch and a cam. Now I'm curious. If it is a micro switch, those can be repaired. Interesting.

Imagine driving near the limit but only able to press the throttle down half way or so. Wish I had discovered the problem with the altitude correction sensor while I was at the track in September.

Likely, masking another problem!