"Home-Brewed" Battery + and - Terminal Blocks Finished Photos Added

I have been holding off on saying this. Grounds and power from the battery is a good filtered low impedance source. The engine grounds via the negative battery cable. Any other ground connection to engine is in parallel. Most modern temperature sensors, crank, cam, WBO2 have the ability be insulated from engine ground, and should be if grounded at battery. If not, If the negative battery cable is loose, the small conductor grounds try to feed the starter motor, and may fry in the process.

Some say there can never be too many grounds.... That is not always true, grounds must be designed to return currents in desired pathways. The electronics in the EFI/ignition does mainly three things, sensor measurements, computations, and controls outputs. There is a carefull strategic ground system, so the control outputs for injectors, and ignition coils do not interfere with the measurement and computation. Well designed systems have desired ground returns designed in the harnesses.

I use engine ground for ECU in my classic vehicles, because the OEM temperature sensors ground on the block, and starter ground drop from battery is avoided from the ECU viewpoint when starting ...