A few years ago, I had a similar problem with the wife's '93 Acura. One day it stopped running, I was busy at work, so I took it to the local dealer. After they messed with it for a day, the service guy told me that they didn't know what the problem was and since it was an OBD-I car, they were unlikely to be able to figure it out without just replacing a bunch non-returnable electrical parts.
I said, "Are you telling me you don't want to work on my car?"
Service guy, "Pretty much, sorry."
I had to go the GM of the dealership to get them to eat the $150 "diagnostic fee", since they hadn't diagnosed anything.
Luckily for you, there a lot of oilhead experts out there.