When damp or foggy, my 1990 Buick Century 3.3 will either not start or start and idle rough. Spraying WD-40 on coil packs and wires helps. I tried click and clack’s method of misting water on the 3 coil packs and wires when idling, and got arching on middle coil, # 2 wire to top of coil pack. Do I need to replace that coil, or just the spark plug wires? The slight mist of water on that middle coil stalled the engine, and it would restart after WD- 40 was sprayed on the coils/ wires.
If this was my vehicle I would replace all 3 coil packs and the spark plug wires as well. I like an engine to start every time and run smoothly. You may also have to replace the spark plugs if they haven’t been changed in a while. I’m very familiar with these coil packs and it’s usually best to change them all when you have a problem. Change just 1 and the other 2 will probably fail within a short period of time.
I concur with missileman. Replace all of them.