1991 Nissan Bluebird not idleing

If there's spark, then more than likely you have injector problems on cylinders one and two. You can check for electricity going to the injectors with a a noid light. Simply unplug the plug from the injector and plug in the noid light and crank the car and the light will flash if it's getting power. If it doesn't there's a problem with the ECM or wiring from it as it controls the injector pulse. You might also have a vacuum leak in the intake on that side of the motor. Spray around with carb cleaner with the engine running. It'll rev slightly when a vac leak is sprayed