Quote:
Originally Posted by dcb
rmccomiskie, can you maybe post a pic of the scope picture?
You are tapped into the switched positive side of the injector circuit?
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There are 2 connectors on the injector. I checked each with the scope. One had no pulses, just noise. I tapped the other one that has the pulses shown below.
Single pulse from ECU @ 30mph (approx. 660uS):
Single pulse from injector @ 30mph (approx. 550mS):
Note the timescale differences. Does that look like a proper injector signal?
Multiple pulses from ECU @ 30mph: (3 inj pulses per rev, 1000/(28mS*3)*60 = 1428rpm)
Multiple pulses from injector @ 30mph: (1 inj pulse per 2 revs, 1000/(90mS/2)*60 = 1333rpm, close enough)
ECU, coasting @ 30mph with throttle closed (flat line):
INJ, coasting @ 30mph with throttle closed (very narrow pulses):
Because of the timescale differences, I assume that the ECU scales the pulses down so they don't overlap when all 6 injector pulses are merged in the same signal.
I have only run the MPGuino off the ECU signal. I have not tried the injector signal directly.