1996 Chrysler NewYorker: car wont start

I bought a 1996 chrysler newyorker, that engine is a 3.5, I bought a transmission which came off a 1997 Intrepid and motor from the year 1995, the yard I bought it from say they are the same as the parts of a 1996 Chrysler NewYorker. I paid a shop to do the labor and they are the ones who help me do the part shopping as well. Now the mechanic who worked on my car can not it to start! And do not want to take no responsability. Very stress but I do know these things for a fact. I am not getting fire. No cam/crank signal and no (Sync). The mechanic are so unproffesional, I was forced to bring my car back home, drove it to the shop and towed it home, it was up at the shop for 36 days. What should I check for to get my car started.