1987 bonneville turns over but won't start

I have a 1987 bonneville 3.8 litre that I isn't firing. This car was running fine until I changed the oil pressure sending unit, which was leaking. I cranked the car to to make sure the leak had stopped, ran it for about 5 min., cut it off and it has'nt cranked since. I have replaced the electronic spark control module and the cam sensor. I was getting a code 41, but the cam sensor did'nt solve the problem. I did'nt replace the three coils because I didn't think that they would all go bad at once. Don't know if I'm wrong or not. Hope some one out there can help me with this problem. Thanks