1990 buick lesaber cuts off while driven. Radio and lights stay on. Changed crankshaft sensor coilpack sparkplugs and wires..

If it's losing ignition during the stalling, replace the Ignition Control Module and retest.
If it's losing fuel then the fault would likely be the fuel pump.
Check both ends of both battery cables to make certain they are both clean and tight.

Replace the Ignition Control Module (ICM).