Sounds like an issue related to the main injection relay located on the driverside fender wall.
Coming out of this relay will be a short pigtail with a round 6 pin plug. With your test light, check for voltage on two blue wires. These go to the injection fuse and should have voltage.
Next turn the ignition switch on and test the black/white wire's pin(ignition switch) for voltage, it's next to the black wire pin(ground). Also verify the ground wire is good. These wires turn the relay on.
On the opposite corner of the plug will be another black/white wire and a yellow/green wire(relay outputs). When the relay is on, both of these should have voltage then too.
The yellow/green wire from the relay turns the ecm on and the black/white wire turns the distributor on.