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Question on adding fuel injection (micro squirt)

wa-chiss

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Ok, I have a great knowledge of engines and how they work. I've seen people using the Micro Squirt system on the CB750 before with success and I'm willing to take the leap. However, knowing how an automotive fuel injection works, there seems to be one key sensor missing for it to work (according to my thoughts). The camshaft position sensor. This is the only way the computer knows #1TDC on compression vs. exhaust.

How does the micro squirt system know the difference without a cam position sensor?

I know the ignition works off of waste spark, is that how the injection works too? Firing 2 injectors per revolution like the coils. Something tells me this can't be the answer, it just doesn't sound like a good system for tuning. This has boggled my mind for a few weeks now. If anyone has any ideas or knows how the system works, that would be great.
 
Not all automotive fuel injection systems use a camshaft position sensor. These type of systems are a batch fire fuel injection system, where paired or a bank of injectors is fired at one time. (most early multi point fuel injection was batch fired) These systems use a different notch in the sensor wheal to indicate #1. Cam sensors are needed in sequential fuel injection where each individual injector is fired. I have no experience with the fuel injection setup you are looking at but I would bet it reads off of a crank sensor and some sort of tone wheel that has an indication notch that the ecm uses to identify #1
 
Yeah, I was looking on a forum at a guys EFI build. He has a reluctor ring on the crank with a tooth missing for #1. He just never went into detail about how the injectors are fired. I guess batch fire was before my time as a mechanic. Makes sense to me now that I've looked it up. Lol. Thanks.
 
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