I don't think it's the fuel cap causing the check engine light on a 95. I could be wrong, but I believe this would be a pre-OBD2 car, so it isn't monitoring the fuel tank pressure. In answer to your question, no there is no "blink" code to find out what the problem is, you'll need to get it hooked up to a scanner to read the code. I don't believe an impulse counter will work on it either, but any scanner that will read OBD1 codes should find the reason for the light......
Gilly