So I swapped out the glow plugs from a good cold starting pajero to mine and no improvements.
My glow plugs were all pretty much white/silver except for the section close to the taps which had soot. It was in near identical condition as the good Pajero's glow plugs.
We compared the timing of the clicks and they were exact. 1 click, 2 click, then 3rd click after a minute or two at normal idle.
The resisitance on the good Pajero's glow plugs were the same at 0.4 OHM.
...So I guess the glow plugs, ECU/glow plug controller and temp sensor is fine.
Next up is the intercooler clean up, then injector cleaning, then injection timing.
I'm pretty sure air leak in the fuel system would be written off as the truck runs fine when warm/hot.
Any thoughts in this?