I would make sure you are getting power to everything in the ignition. In the run position you should have 6-8 volts at the + on the coil and in the crank position you should have battery voltage. You need battery voltage to the ecu, forget which pin, in both run and crank positions. The ecu also needs a good solid ground, I run a ground strap from the ecu to the block to make sure. If you have a 5 pin ecu you need the dual ballast with four connections, 4 pin ecu only needs the two pin ballast. If you have a two pin ballast is it plugged into the correct terminals on the connector?
Have you checked the air gap on the pickup, it should be 0.008", if its to wide the reluctor won't generate a voltage pulse.
The coil should have approximately 1 ohm of resistance on the primary and 5000 on the secondary.
Have you verified that the distributor is turning when you crank the engine? Broken timing chain, cam of improperly seated distributor will keep it from turning.
Pull the distributor and put a volt meter (low voltage range) across the magnetic pick up leads and spin the distributor, you should see a voltage pulse.
This is about all the things I can think of off hand to check.