>| I have an '86 Vanagon that my local VW dealer has not been
>| able to determine the cause of an intermittent problem. The
>| engine seems to ping and knock when I step on the gas (yes,
>| I'm using the correct grade fuel) from a full stop.  At the
>| same time, the tach is bouncing all over the place but the
>| engine is NOT racing.  Then, the engine will "catch" the
>| tach will settle to the correct RPM and the engine has
>| power. I feel as if there is a related problem here, the
>| tach is mirroring something that the engine is doing.  Also,
>| if you hit the accelerator too fast after a full stop, the
>| engine jumps and stalls.

        Check (or have someone check) the 3 wire connector coming out of
the distributor. The elbow can crack and the 3 uninsulated wires inside it
can then intermittenly ground out to the distributor body itsself. The tach
and the ECU use the signals coming thru this connector to determine engine
speed. The tach bouncing all around is somewhat indictaitve of this problem
(if by bouncing around you mean first dropping then coming back up and
maybe oversooting and then back down... it shouldn't go too far over if
this is your problem). The movement of the engine from idle might be enough to
cause this if it is not TOO cracked, but it will get worse over time.
        You can check this by starting the engine and thengently wiggling
the plastic connection of the distributor (should be at about 9oclock when
looking down at it). If the engine starts sputtering, that's your problem...
        I threaded a piece of electrical tape under the connector and that
has kept the van going for 20k+ miles now... Sure beat 325 for a new
distributor.

dave