hi all,

I have put an ls2 with ls3 square port head and a cam in my Nissan patrol. the engine is brand new and never been started before.
i am using an ls1 pcm and efilive v1.2

when i tuen the engine over it goes to start but won't run and i am getting backfiring back through the intake.
what could this be? timing? tune?

could low fuel pressure do it? i am using brand new fuel pump i ordered however i put a gauge on the fuel rail and it is only showing 40 PSI pressure

any ideas would be greatly appreciated.


thank you very much in advance.