jal301

iTrader: (4)

First off, a BIG THANKS to Aaron Cake and all of the work and info which he has shared with all of us. You can find his write-up on proper grounding here....
http://www.aaroncake.net/rx-7/grounding.htm

So, like the titles says, I had all of these ailments. The battery wouldn't hold a charge, the tach would die while driving which was a clue that the engine would soon stall, and I had hesitation all over the board.

So I cleaned up a couple of my grounds but the biggest gain came through making a ground at the ECU. If you'll notice, there is a sleeve around all of the harness wires leading to the ECU on the passenger side floor. I pulled the sleeves off of the cluster of wires and noticed that some of the wires were wrapped in electrical tape. Wanting to clean up any "work" that the previous owner did, I pulled the electrical tape off and realized that this was probably stock since the ground wires (terminals 2R, 3A, and 3G) were crimped together (possibly not all 3 together but there was at least a pair which was joined). So I tied these three together as well as the braided ground wire which surrounds the O2 wire (terminal 2D). All of the ground terminals (including the braided wire which surrounds 2D) are covered with a black cover with brown/maroon dots which makes them easier to identify.

Now note, I am speaking of the ground / braided shielding wire which surrounds the O2 sensor wire and separates once the light gray wire wrap ends - not terminal 2D, itself. Also note that you should use at least a 10 gauge wire or better. I had originally used something too small which overheated requiring some cleanup.

I used Aaron's techniques and created a ground at the ECU cover/kick plate bolt closest to the wires and separated the grounds from the rest of the wire harness in case I have another overheating issue.

Now that this is complete, the car's performance is improved 100%. It now starts so much more quickly and smoothly. I now have a 13V + charge to the battery while driving which keeps it from dying. The engine runs so smoothly now and hesitation free. The tach is right-on, it doesn't drop to 0 while driving, and the car no longer stalls! We're on our way to RX-Heaven!