[Vwdiesel] Pump Timing ---( Gavriks -Injection Pump Strangeness )

[Gavrik Peterson]

>This is the original pump that came with the engine (84').  On the old
>engine this pump did not have this behavior that I am objecting to.
>Actually it was there before, but was so slight that you could just
>detect it if you tried real hard.  Now that I have remounted the pump
>on the rebuilt engine, this behavior has become very pronounced.

When I say that the problem existed before but was very slight I mean
the following:  If you pay close attention when accelerating you can
notice that just as the car gets to the speed where the governor
starts to reduce the fuel, a momentary and very slight increase in
acceleration can be felt.  This effect was so slight that you would
not normally notice it when driving around.  You notice it when you
are deliberately looking for it or are driving alone on a long trip at
night.

>Actually it was there before, ?  ---was the bolt by the lines missing ?

In the past the bolt was there and tight.  This practice of leaving
off bolts is new.  I am getting old enough that it is time to consider
buying my first drool bucket.

If it is true that the missing bolt makes this effect large enough
that it is noticeable, then perhaps when that bolt is present, there
is still enough flexure to produce the slight effect described above.

>Like Loren pointed out it is no ordinary bolt at the lines end.  A taper is >involved. That information will be included in Hillbilly Tuning.  I got one >where someone used a standard bolt.

The bolt I am referring is the one that passes through a big washer
and the elongated hole in the plate mounted on the fuel line end of
the pump and treads into a tapered nut that fits into the U shaped
brace that bolts to the block.  My bolt has no taper, only the nut is
tapered.

>Gavrik try to tell us the numbers on block.  There are two(or more) types of >109 Pumps.  Let us know what you got.   One has the 109 stamped on casting >---the other has a plate riveted with two rivets covering casting numbers. >Black engraved plate.

Do you want the numbers on the engine block, or the body of the pump?
The pump has the following numbers stamped on the casting.

   NR 0 460 494 130
   VE R 136
   068 130 109

>IMHO the 109 pump is worth more money than a 107 pump. The place to get
>correct timing info ---is from BOSCH.  ---- Bosch has a toll free line for >that.

Cool.

>Why would a missing number four bolt affect driving ?  ---this is a guess .
>If it vibrates side to side  ---the fueling sleeve being a big hunk of steel
>may be affected. --- The sleeve controls it all.   IMHO  we are not finished >with this one.-----.

You may be correct here.  It seems to me that without the fourth bolt
the pump could vibrate quite a lot at certain engine speeds.  How this
would effect the operation of the pump, I can only guess.  I have been
unable to come up with any scheme by which static bending might cause
the observed effect. 

If this was an electronic problem we could just slip on a scope probe
and have a look.  I am not set up to deal with mechanical stuff in
such an easy way.  Years ago I had a bad front wheel bearing and was
unable to determine which one.  The only time it would make a noise
was when the car was side loaded in a turn.  I built an electronic box
that acted like a dual channel electronic stethoscope.  You plugged in
two accelerometers that you attached to locations of interest and
listened with headphones as you drove.  Perhaps some instrumentation
like this is needed to dope out this pump behavior.

>PS:  Gavrik I seem to remember that the engine came from a totalled VW of
>yours . years back ?

That's right.  While my 84' Rabbit was parked on the street a drunk
going 60+ mph totaled it.  In the end I chose to start a civil action
in Federal Court to prevent him from discharging his debt to me
through bankruptcy.  That sure was a learning experience!

  --  Gavrik