[Vwdiesel] Adjusting the aneroid

[James Hansen]

It isn't in there. See Bosch manuals.
Assuming the pump is timed properly, accelerator cable is opening the pump
shaft fully, the fuel filter isn't clogged, and the air filter is clean, no
air restrictions, no squirrel nests in the intake.  ALL the basics have been
covered. Check them all.  In general, you look to the pump last as being
your source of trouble.  Timing and most basics are in the Bentley manual.
Get one, it's like gold.

Start with the max fuel screw.  It's on the top of the pump and slightly
inboard, runs horizontal, with a jam nut on right.  (ALL left and right
refers to side of car as if you are sitting in seats, NOT standing in front
of the car, I find this easier to think in this way, sorry)
Loosen jam nut, DO NOT allow the screw to turn when doing this. Then turn
screw 1/8 of a rotation at a time. Turning clockwise increases fuel (turning
into pump housing), counter clockwise decreases fuel.   You are setting the
max available fuel delivery.  This is important, do not screw this up-
tighten the jam nut without allowing the adjustment screw to rotate.  If you
do, you get way more than you bargained for...  There is a locking shield
collar affair on the left side that you may or may not have to remove to
accomplish this. I haven't yet seen on that needed to be removed however. a
little finesse is all that is needed.

Do your eighth of a turn, go for a ride.  Watch for smoke.  If you make
smoke, go back half of what you adjusted.  If not, increase to the point of
smoke making, then back off a tad. Do this all in small steps.  No, that
should read DO THIS IN SMALL STEPS. You can get the fire too high easily
enough, aluminum melts at 1350, allow no higher than 1200 pre turbo to be
safe, lower to be safer.  You SHOULD have an exhaust gas temperature gauge
to refer to in doing this.  If not, well *shrug* you asked. This is how I
approach this.

Now, when you have this set to your liking, ideally clean exhaust at
acceleration, or faint haze of smoke at acceleration (full throttle) go to
the aneroid.

This part shamelessly stolen from Mark Shepherd's post...


But first I'd take the lid off the 'space ship' on the top of the pump and
lift the diaphragm, and check the position of the 'wear mark' on the
ecentrically tapered fueling cone on the end of the bar attached to the
underside of the  diaphragm. This is usually midway between the steepest
side
of the cone and the shallowest. The nearer the mark to the steep side the
more
rapid the boosting  of the fuel under turbo boost, so turning the diaphragm
accordingly should have an effect....If it is already set towards the steep
side , then the problem lies elsewhere...ie the powerscrew perhaps....With
my
car rotating the 'dia.' briefly made my car so lively it felt like it could
climb the trees!  Hope this is a start.  (:o}


Look inside the aneroid, adjust as per Mark, reassemble, test drive.  You
should just see smoke at max throttle for the combination of best economy
and power.  If you go higher with max fuel screw, boost comes in sooner,
less max fuel, boost comes in later. Look at the aneroid as just for
supplemental fuel for when you race at the lights... heh. Watch the heat.
constant black smoke means high egt's, and melted aluminum. this is bad.
HTH.
ps: I'm cc ing the caddy list if you don't mind Mark.  Some guys there
wanted the pump setting info.
later
-James


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