97 cavalier

ok I need some real help here. I replaced my 2.2 engine with a simular 2.2 engine. After we got it installed and locked down,we went to start it, the theft system light came on and stays on, the engine cranks, has gas, but no spark. I had to replace the crank senor because the other one was broken, and we swapped the heat sensor. Nothing else was changed. I have been all over the net reading about the pass loc system, and not sure if I should do the resistor thing to it or not. I had a remote start put in it 1 year prior to the engine change. Its a 2.2 1997 cavalier 4spd, the old motor had 167000 miles on it, the new one has 63000 and it came from a 96 cavalier.Plz help me with this if you can.