1992 Acura Vigor GS the check engine light comes on

I have a 92 Acura Vigor Gs 240,000 miles, it runs great most of the time, but on occasion especially when its raining the check engine light comes on and it runs poorly like it is only running on four cylinders instead of five, and it won't go above 3 thousand RPM's. I have taken it to three shops, including the Acura dealership and they all have come up with the error code 4, which points to the crank angle sensor. I replaced the crank angle sensor, timing belt and water pump but that has not solved the problem. It still messes up and still comes up with error code 4! Have you ever heard of this problem? Or do you have any ideas on what the problem could be Help!