[dcb]

Yup, as long as the pulses don't overlap the diode thingy should work. But the guino is already within 1% accuracy, at least on some cars (my saturn is always spot on), so diminishing returns to start with.

The typical ECU only has one o2 sensor that it makes fuel adjustments with, so all the pulses should be the same length, typically. Not much to be gained by the additional complexity, generally speaking.

But for engines that actually do shut off cylinders (not many), merging the signals with diodes should do it, for the most part anyway. You can tap one injector that doesn't shut off and one that does and cut the usPerGallon in half, I think, hmm...

edit: hmm... went the wrong way with the usPerGallon, didn't I. Lesse... If you have the single injector hookup figure right, then hook up another injector, you will get twice as much injector open time even though the car is getting the same fuel, so you want to DOUBLE the typical usPerGallon if you are monitoring two injectors.