glow plugs!

Possibly corrosion in one of the connectors along the wiring path. Chase back through the wiring, pull each connector apart and check it and the wiring connection into that connector.

hi team troopy
hi dont have a troopy but have a mazda bravo
most of the older sytems have a relay timer between the key and the glow plugs enroute in the wiring

i would guess that it is where you are loosing voltage find that and clean it's terminals or it may need replacing
also i found on my mazda the glow plug threads were allowing compression to escape found this when i was crc ing the side of the engine and put liquid pipe sealer on the threads which stopped the leaks and also made it start easy
hope this helps
cheers barry

yep, grab out your manual and find where the relay is hidden. Cheap plastic black box to replace. Hopefully it's an easy fix :)

There's also a thermostat in the glow plug circuit in the side of the block,which cuts out the glow plugs when the engine is hot.
Mine was stuffed in my old troopy, also check the spade terminals at the sensor for corrosion.
From memory the glow plug relay is somewhere behind the dash, glovebox area, or side kick panel.

I'm pretty had to start on cold mornings too Team Troopy, it was -5 degrees on my porch this morning. But like some of the other have said I think the problem could be the amount of power getting to the glowplugs or the timing of the glow. On my old GU Patrol...I had to wait about 30 seconds past when the light went out before trying to start....and it seemed to worked much better.

There are a couple of different glow plugs available on the 1Hz - hope you were given the correct ones for your model 1Hz.