"from my observation of the ip drip method i think the mb engineers wanted you to use the column of oil in the fuel filter"

But doesn't the filter feed from the top ? Does it say anything about opening up the other side so that vacuum is not keeping that fuel from flowing to the IP as its constant source ? Seems that would not provide enough pressure... it would be more like syphoning.... but with too much constriction behind it... ?

Someone needs to try just putting a fuel source a couple of feet above the IP and setting it... then see if it runs OK...