this is probably a stupid question but i am going to ask it anyway.

I am running Garfinkle fuel rail adapters and i would like know if i can feed the secondary fuel rail first before the primary. Since the secondary injectors are 1300S i don't know if i would starve the 1300s by having the fuel run through the primary injectors while active at higher boost levels.

 

I've been running 850cc primaries and 1600cc secondaries for years now and haven't had a problem running fuel through the primary > secondary rail. I don't think there is a need to run fuel to the secondaries first.

Some use a Y splitter and run fuel to each rail separately like Damain

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fuel-system-upgrade-how-write-up-kgparts-kit-404091/