1989 Camaro wont start

I have a 1989 Camaro RS and the car will not turn over sounds like it is out of gas but its not. I had to change my freeze plugs and I got that done fine and I started my car and it started fine but then my uncle noticed that we forgot to plug in the oil pressure sensor so i shut off the car and we plugged it in and then from then on the car wont start. what can it be someone help?

disconnect the battery cable for about 15 minutes then hook it back up. this will reset the computer. sick

thanks im gonna try that if not ill get back to ya

Check all wires to the oil pressure sensor. The oil pressure sensor provides a path for power to the fuel pump. If pressure drops below 5 PSI a set of contacts in the oil pressure sensor will open and turn the fuel pump off. When the ignition is first turned on the fuel pump relay is enegized for several seconds to prime the system. If the engine starts within that time and the oil pressure is up, power to the pump will flow through the oil pressure sensor (this is not the oil pressure gauge sending unit) and the engine will run, otherwise the pump will stop.