[Vwdiesel] Altitude compensation

[Val Christian]

Wow, 5 psi differential between cylinders!  A couple of months ago, prior to
pulling a cylinder head, I did a compression check on a 91 Jetta NA.
It was 495, +/- 5 across all 4 cylinders, with multiple checks per
cylinder.  I live at 672 ft.  

I have gassers which I'm happy when the compression is within 10%, and
it seems we have diesels which check out to about 1% or perhaps 2%.
Amazing.

Val

> 
> When I checked the compression on my TD vanagon all four were within 5 psi of 
> each other.  3 were 400 and the fourth was 395.  I was a little concerned, 
> but the engine ran fantastic, so I've continued to drive it.  My friend's 
> quantum checked out at 380 on all four.  I recently got thinking about the fact that 
> I live at about 7,000 ft.  When the altitude compensation is factored in to 
> my friend's engine his compression at sea level is 460 psi.  My TD vanagon 
> engine would read 475-480 psi!  Nothing wrong with that!
>