in this video you will see the importance of having the fuel pump in the proper timing by having a properly tune up engine to avoid hard starting issue.
4D56 Hard Start Problem. It's not the glowplugs
https://www.youtube.com/watch?v=6UnCxhE2ElA
COMPLETE 4d56 Tune Up, Valve Clearance and Injection Pump Timing Using A Pre-stroke Measuring Tool
https://www.youtube.com/watch?v=ZiYvfKNNtX0