With any older vehicle, you can run the risk of a previous owner abusing the stuffing out of it and undiagnosed problems. It's also something that tends to happen when you see vehicles on the "Cheap" end of the sales price spectrum. For example, when you see a z06 that's selling for 5-10 grand less than any other--there's probably a reason for that.
I'm sorry to hear about your troubles. My Mitsubishi was the same way; do the maintenance religiously, and it will be dead reliable. Neglect it, and it will haunt you.