you are kind of correct, they can affect the fuelling mixture
Originally Posted by YBJ
Well Claude than I have to correct you because about the crankshaft sensor it also says:
"The ECU uses this engine speed information to deliver not only fuel but also spark advance."
of course it does. but only because it needs to know how fast the engine is turning to look up the values in the maps. if you had an unlikely situation where the engine was doing 5000 rpm, but the ecu was getting a signal from the crankshaft sensor that looked like it was only doing 2500rpm, then of course it would give the wrong fuel amount and spark timing. that would be where the hesitation, misfiring etc comes from
Originally Posted by YBJ
And in a personal email from Stu (MSD) he wrote me about the phase sensor that "It can have an effect on fuelling as it dictates when the injector should open."
true. the fuel injection on yb's is sequential. that means that the ecu uses the phase sensor to know which cylinder is next to fire and injects the fuel at the right time to be sucked in past the inlet valve. if the timing of the fuel injection is wrong, it will not be correctly sucked in and mixed as it would likely be squirted at the back of a closed valve and might just 'pool' rather than properly atomise. all of that is in theory though, and i don't know if it makes a big difference in real life
bottom line is, if you feel something is wrong with hesitation, boost or misfiring or something, don't drive hard until you know the fault. use the diagnostic tools that are available these days to find the problem quickly and easily rather than wasting time and money randomly swapping sensors
