Simple points wouldn't be enough to meter fuel flow. It would respond to changes in engine RPM, but the duty cycle (ratio of on/off time) would be fixed, so the fuel flow would actually be constant. It would need some means of varying the duty cycle and/or the fuel pressure applied to the injectors.
I worked on a friend's '89 VW Cabriolet (rabbit) with a bosch (mechanical) constant injection system. It had a fuel fuel distributor setup with braided stainless lines running to nozzles on each intake runner. The distributor had some kind of pump or hydraulic sensor pickup attached to the engine block, as well as a well-balanced deflection plate placed in between the throttle body and air filter to gauge air flow. As the plate was pushed further and further by increased air flow, it would crank up the pressure to the injectors, forcing more fuel through.
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link:
http://home.hiwaay.net/~langford/CIS.html
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