Sorry guys, here's how things went about this problem last week :
I talked to the Service & parts director (he's in that dealership since 12years so he knows is stuff), and talked to him about my "Sometime the car starts, sometime the car starts on 2 cylinder, and sometime wont start at all" problem..
After a couple seconds, he told me to check the connectors located between the battery and the windshield washer fluid tank (these are related with ignition) . Often, these connectors get loose or get full of "Vers de gris" (greish stuff) and contact is not good.
So i just disconnected/reconnected them, arranged them a bit.. and since that, (one week ago), no more problem ! I played with them when i changed the valve-cover gasket and maybe they got a bit loose, and that's what causing my problem.
Guess What !?
Moderators: Helpinators, Moderators
glad to hear it was an easy fix 
those connectors are the main junction connectors for quite a bit of the car's electronics.

those connectors are the main junction connectors for quite a bit of the car's electronics.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm