something to check out..
find out what impedance the injectors are..
since you have a N/A harness on the car,I am assuming that you have a Resistor pack on the car too?..(silver box,big connector by the passenger front strut,).
The Problem that Can be "overlooked" is THIS: you use HI impedance Injectors and FORGET that there is a Resistor pack on the car..this makes each injector go to 18 Ohms.NOT GOOD.
If you are running HI impedance,splice the pack and By pass it..OR better yet just switch to LO impedance injectors.and run the resistor pack.(ecu sees about 10 ohms per injector).;

never go by the color of the injectors, instead go by the part numbers that are on the sides.

the part numbers are the same tho for low and high impedance