bak bak from the back - ecu or mechanical ?
 

https://www.dropbox.com/s/24jkgon3xw91k44/bak.mp4?dl=0

What do you make of the movie ?

ECU or technical ?

Thanks !
Elior

What kind of injectors are you running at what idle AFR?

rx7 460cc

the afr is just a little rich then 14.7

You can't idle @14.7 most of the time with these injectors.
Start enrichening your idle and see if this continues.

seq inj and 14.7 and it holds no problem.

I'll try 14 or 13.5 just for the test.

Things I would try are :Turn off EGO, if it stops, i would change my EGO Settings, then enrichen the Idle with EGO off, or play with dead times(i think this is a small pulsewidths issue, tho)

What a good pw guess would be for those injectors ?

Sorry, I never use this kind of injectors.
You should buy 4 new real injectors also bro, what's the point of risking your whole build on 89' junk?