> John Russ wrote:
>
> John R. 86 Vanagon
>
> What is ,and where is and what dose it do ? This so called Hall effect
> sender.

        The Hall sender is part of the distributor. It more
or less replaces the old points and condenser. Basicly as
the distro spins, this thing generates a sharp electrical
peak once a revolution. I'd have to take it apart to tell
you just how it does this. Anyway, the hall sender unit
consists of a collar on the distro shaft and a plate in the
distro with some electronics and then three wires connect
it to the outside system. A positive 10 or 12 volt wire,
a ground, and a signal wire. These three wires come out
of the distro thru a plastic elbow near where cylinder
4 will be sparked. This elbow is a connector socket as
well and so there are three spade connector type things
in the elbow. It just so happens that these spade connectors
attach to the wires of the hall sender plate over the metal
bodyof the distro. Thus, when the elbow ages and cracks with
use, the three uninsulated spade connectors are free to contact
the distro body which grounds out at least the signal wire. Without
this signal, the ECU and tach do not get a timing/rpm signal and thus
think that the engine is not turning and never getting to a point
where a spark should be delivered. Thus, you get no spark and no
fuel delivery...

dave