Why wont my Jeep Cherokee XJ start or turn over?

[Shane]

I just recently swapped engines in my 1988 jeep cherokee xj. The engine that was currently in it started up and ran just fine. It was high on mileage so I decided to swap it out with a motor with low mileage. I swapped the motor from a 1987 jeep cherokee and put it into my 88 jeep. They are both 4.0l but one was a manual transmission and the other was an automatic. I currently have the automatic installed. Everything is mounted and plugged in. I went to start it for the first time and all i got was this fast clicking/humming noise. So I figured it needed a new crankshaft positioning sensor. So I installed one of those and nothing. I fooled around with it a little more and eventually got it to turn over, but it still wont start. So I figured it needed a new coil...went and got one, installed it and now it wont turn over at all. I checked all the fuses and they are fine. It now has a brand new crankshaft positioning sensor and coil now. I know fuel is getting to the engine, I checked that already. It is full of new oil. When I bought the coil I was going to check for spark but now that the jeep wont even turn over I don't know what to do.