Injectors not firing. Fuel pump working and fuel Rail has correct pressure?

Injectors not firing. Fuel pump working and fuel Rail has correct pressure. Fuel filter checked and changed, no contaminates found in fuel. Injectors removed and checked for contaminates, non found. +13 v present at injectors with ignition in run position. Spark present at all plugs indicate that distributor is at least partially working. There are no codes stored on ECU. I understand that the ECU uses a couple of signals to control the Injectors, such as the neutral switch and a starter signal. The igniter (located in the distributor) may also provide a signal to the ECU for Injector control, is this correct? If so how could I check for this problem? And could there be another problem elsewhere? Any help appreciated.