[Vwdiesel] Outlet on Turbodiesel Injection Pump

[Tyler "Casioqv" Backman]

If the pump actually has a extra port for the boost enrichment vent,
what if one where to hook that to a sealed metal tank as a reference
pressure, so that it kept 14.7psi at all times? Wouldn't this make the
fuel metering more accurate at high elevations (for climbing mountain
passes, etc.?) It would have to be big enough to not alter the fuel
curve much as pressure increases when the aneroid moves. It seems like
otherwise it would think that you are running more boost than you are,
and run excessively rich, which could cause high EGTs, which is
especially bad when climbing a steep grade in thin air with a heavy
load. Is this what the altitude compensator does (I think I read in a
manual somewhere that these were equipped on models sold at high
elevation)? I am also thinking about removing the wastegate from my
turbo after I install a intercooler, because it never runs full boost
anyway except when ran very hard, slightly more boost is okay with a
intercooler, and the wastegate gradually opens as boost increases, which
likely causes it to spin up slower, and run a little less boost at
cruise. The test Nate did without a wastegate makes it seem like running
without it isn't a problem, any ideas? Do you think maybe his car is
under-fueled? Also, does anyone have an idea as to how much boost can
safely be run on a VW Diesel? I know many other turbo diesel engines run
well over 30psi. I would think that the stock Garrett should be good for
20psi or more (obtainable with more fuel and no wastegate?) with a
intercooler, without too much heat, the garrett is a pretty good sized
turbo, but I haven't looked at the maps to see how much heat it would
put out at these pressures. Also, if the aneroid adjustment is the main
thing that determines maximum boost with no wastegate, than perhaps that
would be a good way to set the aneroid adjustment without a EGT gauge (a
boost gauge is much cheaper, and easier to mount). I am still not sure
how I am going to mount my EGT gauge in the stock exhaust manifold, but
I do have a manifold from a newer engine (that had a PCV valve port) and
possibly a small plate could be made to cover this port, and include a
welded on nut, to provide a place for a EGT sensor.

-Tyler

LBaird119 at aol.com wrote:
>   If it's down in the body of the pump or aneroid lid then it's just the vent
> for
> the lower section of the boost enrichment diaphragm.  If it's on the lid then
> it's for boos enrichment and connects to the intake, post turbo.