Suzuki: 1996 sidekick 4x4 1.8L, mechanical problem, heater core

Question
My old engine went out and I recently replaced it with another used complete engine. I can't get the motor to start. When ignition key is turned on, a clicking noise is coming from the EGR and a connection on the heater core case. Also sounds like the injectors or purging. I've added additional grounds thinking that would help but still nothing. The engine will not attempt to start, just hear clicking. Could it be the ECM was damaged?

Answer
If the starter works, does it have fuel pressure?  Are the injectors actually firing? Does it actually have spark, and is the cam correctly timed, and the distributor correctly timed?  
If one of those is measurably not operating, then you know where to start and diagnose following backwards from the non-functioning device.
Did the old motor suffer a mechanical problem that kept it from running, or was it for another reason, and was that reason diagnosed prior to replacement?