microsquirt blues

[Piledriver]

Maybe I'm missing something here..

But, if the engine is grounded (via chassis or cable) how does it make a difference to any of the MS parts if it's terminated to the the engine or the actual negative terminal on the battery?

Grounded is grounded.

...I can absolutely assure you that "ground" is a relative thing... a very convenient construct for mentally groking how things work.
It's an idealized concept to let EEs sleep at night.

I can also assure you that ground is not ground, ever, and no two grounds are exactly the same, and if they are, buy a lottery ticket.

Particularly...grounds that have current flowing through them like... cars, car bodies, wires, engines etc have voltages at each end that are guaranteed to be different, and will vary with current.

Lets not even discuss RF shielding/grounding. Please. That's when it starts to get weird.

Follow the fine manual for everyones sanity.

[miniman82]

Pile is right, that's why MS has internal sensor grounds so there's no noise. If you were to ground all sensors at the block for example, any issues with the block grounding or battery will be fed back to the ECU and represents an unintended error signal the ECU cannot compensate for. Best thing to do is gound all the sensors back to MS, and make sure there is a heavy grounding strap on the block and transmission back to the battery and chassis.

[Hoodrich]

The sensors are all grounded to the MS, the ground wires from the MS are on the engine block now per instructions


Thanks for all the help guys!