Mercedes w123 200D engine shaking issue

[Merc123-200D]

Hello i am new here and I would like to get some tips from you. When i start the car especially if the engine is cold the engine shakes like it's going to stall and when i give it a little gas it works better and i keep the idle a little higher. But again when the engine is warm it feels like a tiny millisecond break like there's air in the hoses or something. Otherwise when the car is driving it runs fine. Can you help with this I would be grateful.
I was changing the primer pump because the old one was throwing out a lot of fuel when it was pumped and I also changed all the rubber high pressure hoses that go around the injectors, fuel filter, oil filter, oil, air filter and I thought this would solve the problem but again it's not that.
The glow plugs are new.
Please help I would like to get rid of this annoying shaking