smell the oil and see if it has a gasoline smell, if it does it runs too rich. is the engine temp reading ok? what about IAT? it's a bit strange to get fuel in the intake, only way to get this with MPFI imo is if you have a leaky injector (not closing so it squirts all the time). or maybe an intake valve that's not closing so it blows back towards the t/b on compression but i think in that case you'd know it runs in 3 cyls and not get better in time.