Help, I have a 1997 Cavalier with an OVC engine. My problem started about 2 months ago. When it rains my check engine light comes on and the engine begins to miss badly. The tach goes up and down and there is a loss of power. I have had it to 2 different garages. I have had it tuned up, replaced the fuel injectors, the coils and it is still running badly. When the garage puts it on their computer it does not pinpoint the problem. They have replaced the new spark plug boots that were installed by the first garage and cleared the trouble code. It runs for a few days OK but when it rains, it starts all over again. I have attempted to put in a new crank shaft sensor but I can't find out where it is on the engine. I was also told it could be an ignition module. Any help would be greatly appreciated. Thanks

try putting water in a spray bottle and spraying the ignition module and then try starting thet may be your problem