Quantum d4d 2.5 has hardstart in the morning until I push start. If I keep cranking engine for a long time the engine shakes vigorously. While cranking if engine light disappears engine starts. If light stays on engine doesn't start. During the day no problem. Changed diesel pump and injecto
If you are having hard starting in the morning the first thing I would check is the glow plugs. The glow plugs are meant to warm up the engine so that it can start properly, if they are worn or faulty then the motor can have starting issues such as the ones you are experiencing.
If you decide to get this fixed, I suggest getting some help from a qualified technician who can diagnose your hard start and make the necessary repairs.