Signal return grounding question
How have you guys with aftermarket ECUs and rear mounted batteries run your grounds so that you are experiencing minimal noise in the signal return. I've got what feels like excessive noise in the TPS and MAP sensor but I'm wondering if it is a function of poor board design or sub-optimal grounding.
I have an AEM EMS and I am getting ~1-2% fluctuation in TPS percentage due to what I can only presume is noise in the signal. I know the value should fluctuate a little bit but the numbers that I'm seeing seem a bit excessive and is making the car drive a bit rough. I want to make sure my house in in order before I take a deeper dive into the electronic hardware and possible poor board design in terms of ground isolation.
My grounding is as follows:
-0/2ga wire from battery negative to rear of spare tire well
-0/2 ga wire from engine block to passenger side frame rail
-OEM body ground in factory location in passenger foot well
-OEM quick disconnect ECU ground to unibody behind rear shock tower
-OEM braided line from passenger side cylinder head to firewall
Some have said that running a large diameter wire to the engine block using the point where the battery negative connects to the chassis is required. I'm no electrical expert but I a wire would be a higher resistance conductor versus the chassis of the car. I've had several cars where the factory installed the battery in the rear and there wasn't a long ground wire from battery negative to the engine in any of them. The factory used the body as the conductor.
Thanks for any help.