'89 240sx Cranking..But Won't Start
 

Hi,

As the title says the engine is cranking but it won't start.


I have replaced spark plugs, wires, distributor cap, and rotor.


Fuel pump is checked and good, injectors have been checked and shooting fuel.

Spark plugs:

2 of the plugs give off a weakish yellow spark, 2 of the other ones give off a white spark or a big yellow spark.


What should I do? At a complete loss here, been working at this for almost a month in between work and school and I'm getting ready to just sell the car. It seems everything is right, fuel, spark, and I'm pretty sure there is air?