i guess there was a load of unburnt fuel in it from you trying to start it and when you put the glow starter in it may have ignited vapour in the cylinder which then ignited the fuel air mix in exhaust , any way its only thing i can think off and was probably a fluke it happened
just reread what you said about the glow plugs , isnt the os 4 quite a hot plug ?
i know the os8 is medium and os 6 is hot so going by that os 4 will be hotter maybe your needing to go opposite direction with the plugs into the cooler or cold ranges ?
hiya and welcome back to the world of nitro's
im sorry but ive no idea on that car so will let others chime in , only thing i can think offhand tho is have you tried a google search for the car as there should be some diagrams drawings somewhere on the net