J&S ecu for 5kT

[Orin Eman]

> I don't really know for sure how the J&S works, but I thought it was it's 
> own autonomous ignition system, and does not rely on the oe ecu for 
> anything. The reason I thought this is b/c it requires a rpm input, and you 
> can apply it to cars w/o ecu's.

No need for an ECU to generate timing... centrifugal advance and
vacuum advance/retard units along with the position of the distributor
did it for years.  Then either points or some kind of magnetic sender
to fire the coil.

An RPM signal is nothing more than the coil drive signal...
most tachometers are driven from the coil.  Though there is a
separate tach signal from the MAC11 at least which looks like
a coil signal, but without the same drive capabilities as the
coil signal.

> oh ya, and I think if you just put a resistor [equiv. to the Bentley spec 
> for knock sensor] across the ecu's knock sensor inputs, the ecu would think 
> everything is fine...

That won't work.  The knock sensor is a microphone and the ECU
expects a certain amount of signal from it.  If it doesn't get
enough signal, it throws the error code.

Orin.