To replace the ignition module in your Celebrity:
Unplug the wires, take note of where they go so you can put them back in the correct place.
Remove the screws that hold the ignition module in place. If the old module was coated with dielectric grease on the mounting surface put fresh dielectric grease on the replacement ignition module. Put the new ignition module in place and attach with the screws. Plug the wires back in their respective places.
On the V6 the ignition module is under the distributor cap.
You can replace the ignition control module and the crankshaft position sensor as required.
The ignition module on a 1988 Chevy Celebrity with 2.5 engine is on the side of the block beneath the intake manifold. You can simply follow the spark plug wires to it. As information the crankshaft position sensor is behind the ignition module.
All 1987 to 1990 Chevy Celebrity engines use distributorless ignition. Timing is controlled by the engine control module in conjunction with the ignition module. There is no provision for adjustment.
Which engine does your car have?
On a 2.8l v6 it is at the front of the engine behind the ignition coils.
I take mine to Autozone, they offer free testing of ignition modules.
The 1988 Chevy Celebrity uses distributorless ignition. There is no provision to alter timing, the engine control module takes care of that.
The 1990 Chevy Celebrity engine is distributorless, the ignition is handled by a combination of the engine control module(computer) and the ignition control module. You did not mention which engine the car has. If your car has the 4 cylinder engine the ignition control module is below the intake manifold at the rear of the engine. You can follow the spark plug wires to it. The coils are mounted to the ignition control module. If your car has the V6 the ignition control module is near the starter and again you can follow the spark plug wires to it. Again the coils are mounted to the ignition control module.
I would suspect a failing ignition control module.
The coils are bolted to the ignition control module, there is no coil wire as such.
The 1987 Chevy Celebrity has distributor less ignition. The timing is controlled by the engine control module and there is no provision for adjustment.