Dual knock sensors with CISIII?

[Marc Swanson]

> So I've got the two knock sensors sitting in front of
> me from my MC-2, I'd like to rig up a dual knock
> sensor CISIII ignition.  Any one know if that's
> possible using the 90q ignition with the MC-2 sensors?


They certainly look very different and attach to the block differently.  The
MC-2 (assuming the sensors are the same as MC-1) screw into the block while
the CIS III sensors attach with a bolt through the sensor body.  No doubt
they produce different waveforms.  I bench tested a CISIII sensor in an EE
lab on campus at UNH and if you get the thing to resonate it produce a nice
little rippled wave on an o-scope.  The shape of the wave is very important
as the ECU has to interperet what is knock and what is normal engine noise..
thus I can bet that their resonant frequencies are quite different since
their shape is very different.

As far as using dual sensors on CISIII I'm not sure... you'd have to splice
the two sensors together and that alone has the potential to create some
unwanted noise in the circuit.  That coupled with the fact that the ECU is
not expecting to encounter 2 signal sources on the same line....

Later

-Marc-
87 4ktq
88 90q