My 93 300se engine will turn over but won't start. It has always started immediatly but gradually it took longer to kick in. I then began starting it by pressing the gas a little (which I know I should not do). I replaced fuel filter, fuel pressure regulator, wiring harness 1 year old, battery, and I sanded the rotor and distributor cap so that they are clean. I used a spark plug tester between the distributor and spark plug wire and did not get a light. I also smell no gas. Right now i'm waiting on my new cap and rotor to come in. Any ideas ?