Cold start and inconsistent turbo

When I start my car in mornings or after it stands for over an hour, the car swings for a long time before it starts. When it starts a lot of smoke that smells rich in fuel is released. When engine is warm car starts on first swing with little or no smoke release. During driving very little smoke released from exhaust. I have replaced all four glow plugs but still same result. Could it be that fuel pump is not giving enough pressure or should I reconnect the injectors?
Turbo kicks in between 2 and 3 thousand revs. Sometimes it works perfect most of the time it kicks in then seems to lose pressure. Especially when I go up an incline. Could this be the injectors, a faulty turbo or maybe the airflow management.
Thanks for any information.