Turns over but will not start

Okay, I had a bad oil leak so I changed my valve cover gaskets. When removing the spark plug wires I discovered the cylinders were full of oil. So I replaced those gaskets too. I wanted to know if it fixed the leak, so I sprayed degreaser all over the engine and everywhere there was oil, then took my little electric pressure washer and sprayed it all off. Then when I went to start it up, it just cranks but will not start. I have checked and charged the battery, made sure the distributor was dry, checked the air filter, the starter wire. I am lost. I checked to see if the plugs are firing and it is weak but they are.