I own a 93 legacy 2.2 L 2WD wagon. It starts sometimes and sometimes not. It turns over but doesn't start. I have replaced the battery, alternator, and a relay of some sort. It will start and then maybe later in the day not start after running perfectly fine the whole day. It seems to be getting worse. Usually if I wait 4-24 hours it will start again and keep starting for a few days. The mechanics I've spoke to suggest it could be a coolant temp sensor. Could that really cause the vehicle not to start? I have no other symptons. When it runs it runs great. It seems to not start more often when it's very cold outside. Any idea?

I would stick with the coolant temp sensor and possibly plugs as well.