just replaced AC comoressor now it is cycling on and off high pres. line is hot

What is your question?

I just replaced the engine along with the compressor because the clutch was making a clicking sound. Added the right amount of oil and Freon and was cooling at first now is not cooling at all and the high-pressure line is getting very hot when compressor clicks on and it is short cycling. Also had a problem with a blocked heater core I don't know if this is related to the problem with the AC. I found out that this could be due to a blockage in the system, I plan on changing the orifice tube. How do I determine where a blockage is? The system never gave me a problem before changing the compressor, I don't want to go replacing parts unless I can determine exactly where the problem is. Thanks