I got a 2002 4.0 tj. I got a rebuilt 4.0 motor from a parts store to replace the old one due to broken pistons. I just got everything hooked up, put back to its place. I drain the gas tank, put new gas in, and added all the fluids it needed. When I tried to start it, it would try to start but it wouldnt and it would back fire every now and then. I dont think its the timing bc when i got it, it was already in top dead center. Any suggestions on what could be holding it back from starting?
