Quote: What you MUST remember about ANY ECU, is that it is a microprocessor and is such is sensitive to outside influences, sometimes regardless of the filtering. Plus the filtering can NOT protect the box from outside sources anyway.
Here is a rundown of how I have been wiring EFI cars for a few years and so far, I have had ZERO problems with noise.
I make a copper buss bar about 1.5" wide and 6-8" long. I drill holes varying from 1/4" to 3/8" along it's length. I then mount the buss bar under the dash on rubber isolators, like comes with an MSD box. I run a minimum of a 1 gauge wire directly from the battery to buss bar. I then run a 1 gauge wire from this same buss bar post to the motor plate and from motor plate to each head. That is all that is on THIS post on buss bar. The ECU power and ground runs directly to battery. NOT the cutoff, but TO THE BATTERY. All other items, like pumps, fans, coils, etc, ground to various lugs on buss bar. Now obviously, with a ground running to motor plate and heads, the chassis itself IS grounded, but it is NOT my primary ground circuit. And as I said earlier, the only thing I actually ground to the chassis or sheetmetal itself, is the lighting circuit. I also ALWAYS use a Ford starter relay on ANY car I wire. This and use a LARGE cable from batt to relay and from relay to starter. This gets you FULL battery power while cranking. I also do NOT stack a bunch of 12 volts feeds for other items on the relay itself. If I need other feeds, I run a 1 gauge cable from batt side of relay, to an isolated terminal stud to pick up power from. You may say that's "the same as" stacking feeds on input side of relay.......NO, it's NOT. Also use a "shielded" trigger wire on the crank and cam sensors. Given the option, ground the shield through the ECU itself, or INSIDE the car on Buss bar...NOT on the engine end. Be sure and run the cam/crank sensor wiring by itself and totally separate of ANY other wiring where possible. "In the harness" with other wiring, about guarantees you a problem.
Hope this helps
Monte
Street Car, Race Car, Street Car named Desire, this sounds like the sure-fire way of NOT running into any issues with electronics, which I believe is his point.
