Black smoke after replacing turbos and injector

 It could be due to the intercooler.   Signs of defective intercooler:   black soot and oil at the underside from the leak.

Why some cars wont start?

The answer is not in the keys.  It is in the pairing of the keys and the starter button.  There are stories where cars dont want to start and mechanics have changed from all sensors to ocils and injectors.  Only for the scanner to show that something is wrong with the key programming.

So the first step really is to think electronic.  We need a sort of password or registration.   First step, have your electronic engine scanned.    

Repairing, restarting a problematic .... suv

 The initial fault was the electrical of fuel system, the car still wont start.   Then they went to the second fault -  the crankshaft sensor and the E.... engine finally started