Update, had already fixed the broken glow plug. We had no choice but to remove the cylinder head. Pushed down the broken tip until it fell into the precombustion chamber. cleaned the head, lapped the valves, changed valve seals, etc (we used the OEM top overhauling kit from toyota). I had to change the nozzle tips as they have seen better days. The result was a "1-click" start, a quieter engine with decreased emission with stronger pull and probably a satisfied owner. Lesson learned is, the moment your old school diesel present with hard starting in the morning (with a good battery and starter of course), check your glowplug immediately and replace as necessary. Even if your old plugs seem physically ok, it is still best to check their electrical resistance to know if they are still good. It is also wise to clean the glow plug hole with carb cleaner to reduce/remove the carbon deposits that can seize up your glowplug in the future. And if budget permits, use OEM glowplugs, they last longer than replacement ones...

downside lang is gumasto ako. Man!