Postby Mosaic » May 13th, 2010, 11:30 am
Proper grounding is quite important, its not just for helping your sensors operate within spec. You car is full of relays, motors and solenoids, each of which generate inductive voltage spikes when operating. These spikes travel down the power lines and will frag assorted electronics. Proper grounding helps minimise the level of these spikes. If your grounding is poor you will get these spike transients of several volts.
I have measured transients 3V in peak, about 20 milliseconds duration due to poor grounding. Think of what 3V can do to say a 3V MAP sensor signal. How does it get into the sensor signal if it's on the ground line, you ask?
Because the sensor references the ground when outputting its signal. So suddenly you have weird fueling transients and u can't figure it.
That's why u need a proper electro guy when modding your car, DO NOT share ground wires with sensors & electromechanical devices. Do not UNDERSIZE power wires. DO NOT run POWER wires and sensor wires side by side, unless you run both the sensor ground & signal on the same path so both pick up the same transients for a net zero effect. DO Place clamping diodes reverse biased on any relays or solenoids you add.
If u need the clamping diodes, I know where you can get em for $2.00 ea instead of $5.00