"Work" all the connectors in/ out several times, pull them off and inspect with a flashlight for corrosion. "Feel" for how tight they fit.
Make ABSOLUTELY certain the ECU is grounded.
Turn the key to "run" measure coil PLUS and coil NEG to ground. The coil PLUS should be somwhere between 6--10 volts. If it's lower you have a problem, if it's "same as battery" you have a problem AND MOST LIKELY ECU is ungrounded
Coil NEG voltage should be fairly low, perhaps 1/2--2 volts. If it's zero, the coil is open or the ECU is bad. If it's way higher, near battery voltage, the ECU is not grounded or ECU is bad
If you have a tach remove that wire.
Remove the dist connector and take up the ECU end of the connector. With the key in "run" tap the exposed dist. terminal on the connector to ground. Each time you do that, you should get a spark.
DISTRIBUTOR
Especially "work" the dist connector in out. These are trouble. Check resistance of the pickup, should be 2-500 ohms. Set your meter to low AC volts---that is right AC volts and connect them into the dist. connector. Crank the engine. The dist pickup should "generate" about 1V AC
Inspect under the cap, inspect the rotor for "punch through." Inspect both for moisture, tracking, dirt, etc. Inspect the pickup and reluctor for "strike" damage, and rust and debri. Check side play of the shaft for wear.