i've researched this topic and found that people are grounding many things on the ecu. first fix said that you should ground 2c-2r-3a-3g. which are located on the center connector. to the chassis. the second fix said that you should ground the solid black wire that is bunched up with the 4 green wires on the far left connector.
ok my problem is the first fix with 2c, that one doesn't seem like a ground and where is 3a-3g. my second problem is the second fix. i don't have a solid black wire on the small far left connector i have 3 black wires with various striping.
i would like to ground my ecu, but which one is the main ground!! i have a 87 tII

 

Under WOZOOM's site, you'll find the ECU regrounding. I've done It and can verify I didn't blow up anything.

http://wozzoo.tripod.com/ /modtech/ecuregrounding

Here you will find a wealth of Info. Jeff's the man.

 

Here's another how-to on upgrading the ECU's grounds.
If you have the FSM wiring diagrams this job is extremely easy. I highly recommend you download them from www.fc3s.org or www.iluvmyrx7.com. The plug diagrams make things very clear.

 

A man... not "THE" man. But thanks anyway. I just wish I could finish updating my site.

Anyway, the thing you have to remember about ECU grounding is that almost every wiring harness is different. I've had about 20 people write to me about my ECU grounding info and they all said: "I don't have that". Just follow the ground terminals out of the ECU and you'll be fine.