Chevrolet Repair: Cadillac Engine Replacement, cadillac repair, auto mechanic

Question
It is listed that you have Chevy experience so I thought I would ask knowledge on Cadillac repair.  I am also an auto mechanic (do in spare time now).  I have replaced engines in almost every manufacturer and not had problems.  However I am stuck with the engine replacement on a 1999 Cadillac 4.6 liter engine.  The replacement engine I purchased in great shape from the junk yard with only 6000 miles on it.  Everything was installed correctly down to the electrial.  However I am having an awful time trying to get the engine to start.  I have retraced the steps and have discovered nothing left out or missed.  Also checked for an alarm and it does not have one.  Is this something manufacturer based?  Just wondered if you have ever come across something like that.  Thank you.

Answer
Hi John, I haven't worked on too many caddys but Lets start at the beginning. What are you missing for the engine to start? Spark or fuel!! You have fuel pressure? The check engine light comes on at key on engine off? Does the SECURITY light come and not flash.

Let me know on these and I will try to help

Mark