I replaced the head gaskets and the timing chain on a 2010 nitro 3.7. Got it all together and had it running but has a cam and crank position code. I replaced both sensors but still had the code. Sooo I had the timing wrong. Tore it all apart and redid the timing. Put it back together end now my truck will not start!!!???!! I checked all my injectors, and firing order! What could be the issue? Please help!!!!