Make sure you keep replacing distributors and modules, and maybe a coil--without doing any diagnosis.
Absolutely do not perform a cylinder-balance test by sequentially shorting-out the spark to each cylinder in turn, and watch a vacuum gauge to see how much the intake vacuum drops with each cylinder. Any cylinder that gets shorted but doesn't drop vacuum is dead; a cylinder that's shorted and doesn't drop vacuum as much as the others is weak.
Do not connect a scan tool and view the data stream. Don't verify every sensor, and don't assure that the computer outputs seem reasonable.
Do not verify fuel pressure.
Do not check for vacuum leaks at the accessory hoses like power brake hose, or PCV hose; or inspect for failed intake manifold gasket(s) or throttle body base gasket.
It's completely possible that you've had multiple distributor/module failures, and replacing the coil and the module together could fix it. And if not, maybe you got more defective parts. Try again. And again.