I have a transplanted OM617 turbo into a 1988 4runner.
I have had the pump updated to 7.5mm elements from a reputable source using Dieselmeken elements. Injectors cleaned and balanced by greaser, valves adjusted with plenty of clearance.

Before the upgrades, the engine was running smoothly. Now, it starts fairly easily but immediately begins loping or surging at idle. It seems to be fine at higher RPM. I have adjusted idle speed, and adjusted the rack damper several times with no improvement. The lope is approx every second. The rack damper adjustment can sometimes slow down the frequency momentarily - but it always returns. The longer I let it idle, the more severe the lope. This isn't the typical idle shake that many threads exist for, this is severe. My working theory is the idle governer is improperly set, but that is an invasive job to undertake. Looking for suggestions on what i might have overlooked.