Cranks but wont fire iM getting fuel, its cranking good?

My 1990 civic lx will not start. Im getting fuel, its cranking good, and I have spark. All fuses are good. I put new plugs in last year. I have an oil leak that is getting into one of the plugs but I have pulled them and cleaned them all well and last year when I replaced the plugs there was oil in the same one but it has never caused a problem. This car has never had a problem before with starting. My intake is clear and so is the exhaust. I do not have a muffler though. It rusted off a few months ago and I have not had time to get a new one installed, so I am running straight piped. Please, if you can help I would greatly appreciate it. My girlfriend and I both work full time and are full time students in college and we share the car so it is something we need to fix asap.