IP timing

[Isaac Peter 70]

Hello ,first of all I'm new to this Forum and I have been looking around which site is helpful about om617 Diesel Motor , this is kind of new to me I don't know much about Diesel om617, I bought a 1983-84 Mercedes-Benz Turbo 300D , cd or what ever model is this about 2years now , so anyway I recently remove the IP and send to Bosch for rebuilt , and they did a really good job looks like brand new , but its been frustrating on my part because I did exactly what they told me to do and how to remove and install back into the block , line up the timing to the groove at 24*BTDC I did all that for several times to get the timing correct , I bleed all the lines but its still same results rough idle seems like misfire and lots of white bluewish smokes , and ping weird noise like valve and piston hitting each other , I also adjust the valve clearance and new Monark Nozzles , I'm like giving up already just to get the IP out is pain in the Butt, so I decided to pull the Engine out and do it on the side and get it run right before put it back in , I did some research and said in this particular IP you need to set the IP to 24* BTDC yes I did that … but there is another timing in this IP said you need to turn the engine and set the timing to 15*ATDC ,so like what the hell now , bad enough where on earth I don't understand I'm lost .. anyway I would like to get to the bottom of this anyone know what or how to set the IP to 15* ATDC? went to far to give up now ..I will post a picture or video how it runs maybe anyone know what the problem is ..