John_Forbush wrote:And to time the pump I was thinking of maybe setting up a crank trigger.
It can be done, the trick really would be getting the timing right, plus something to power the injector.
Look at any automotive Hall Effect Sensor and you can probably rig a sensor and bracket to time off the flywheel magnet (or drill a hole and a trigger pin in the flywheel where required) Some sensors may work off leading edge, others off trailing edge, then you will need the controller to tell the solenoid in the injector when to fire, and for how long to remain open vs how long to remain closed (The duty cycle). (that affects fuel-air mixture ratio, and also must take into account the system pressure, which really should not vary, so you need pressurized system plus a pressure regulator) You could do a "limp mode" where the duty cycle is pre-set for certain RPM ranges , but that results in waste and horrible fuel efficiency, so you will need to have a mass air flow sensor to determine air volume, and possibly a throttle position sensor to determine throttle opening... Or, a Mass Air Flow sensor and Air Temperature Sensor. So as you can see, Electronic fuel injection *is* possible, but you'll need to do a lot of R&D to get it right.