my car was supposed to be tuned yesterday, but as soon as i hit 10psi, i get really bad breakup. my AFR is between 10.9 and 11.2 under load so we ruled out too-rich conditions. I had this same problem before converting my FD to to single turbo. I used to have to take my PFC and twist the whole thing with the harness still attached to make it work right, and then shove it back into the kick panel with the wires held in a certain position. Obviously it's a bad connection in the harness or the PFC, but which bad connection would cause this? My car runs perfect until i hit 10 psi and no less.

 

I have had break up when I went single over a year ago. I changed the plugs to all 9's and now I don't have break up! You can give that a try, worth a shot.

 

already running 9 plugs all around

 

What mods are done to the car?

 

its obviously a bad connection in the harness or ecu, he stated that already, has notihing to do with plugs or other mods.

did u not post a while back that u bought a new harness trying to fix your issue?
were u able to get access to another ecu yet? that would be your best bet. do u have a buddy or someone u can borrow one from? maybe buy a used one and try it out. re-sell it if it doesnt fix the issue. like i said before, i know of a few power fcs that have crapped out causing cars to fall on there face as if they were running super rich.

 

i did make a post awhile back but it was a bad CAS connector. this is a different issue, but same as i had a long time ago. i just want to know what particular wire would cause this problem.

Mods:

T-76
CJ Motorsports Fuel Rails
Bosch 044 Pump
720/1680cc injectors
MSD 6AL on Leadings
Blaster SS Coil for each plug
Apexi 3" turbo back
PowerFC
AVC-R

 

anyone? suprised no one else has this same issue

 

I had the same type of issue on mine, and an HKS Twin Power alleviated the problem. I see you're running an upgraded ignition, but I wonder if that would solve your problem. Can you run a Twin Power and your ignition at the same time? The Twin Power is just a restrike, not an amplifier, so I can't see why it wouldn't work; then again, I don't know too much about the ignition field

 

if u read my first post, i had this problem before i went single and did any of the mods listed above. all i had was a FMIC and Apexi intakes/exhaust with a PFC and AVC-R. it's something in my harness i know that for a fact. I just want to know what wire to replace

 

check this out , i believe we have the same problem ,
https://www.rx7club.com/20b-forum-95/20b-maps-766895/