[urq] Finally re-assembled engine and car...won't start

[Buchholz, Steven]

... still going through e-mails ... but thought I'd respond to this one
... apologies if anyone else has already done so in a subsequent post.  

It is quite a simple test to loosen the distributor and rotate it a
little to test your theory ... I did some reverse engineering of the
MAC-02 and found that there is a logic AND gate in the circuit that
provides the reference sensor signal to the processor, this gate allows
the signal from the reference sensor to pass through only if the Hall
signal is in the active window.  On newer cars the circuitry is a bit
more sophisticated, but on the urqs which use the MAC-02, if a problem
develops with the Hall Sender or the relative timing changes the engine
will cease to run ... 

Steve B
San Jose, CA (USA)
> 
> The TDC sensor is in the top of the bell hosing. It reads a pin on the
> flywheel. It is a much more accurate way to measure the 
> position of the
> crank than the hall sensor. However, being a 4 stroke motor, 
> the pin passes
> the sensor twice for every revolution of the cam. The hall 
> sensor is used to
> determine the correct pass of the pin to use for ignition 
> timing. I have
> heard that this comparison only happens during the starting 
> of the motor and
> once running, only the flywheel pin is used. However, on a 3B