Question concerning glow plugs
something else on the plug.
if you look at the coils, they are in a coil and not smashed, but looking at the wire it should look clean.
some plugs that last a while in an engine and then the engine starts acting-up the plug went bad, but the coils are still in the correct shape. but looking at the wire you wouldsee the wire is "rough" like it was sanded, if you know what i mean,
the wire lost its coating and not holding the heat correctly. if usually only seen the hight quality(os, etc) last this long. but replacing with a new plug, even temporarly , diaganois this problem quikly.
just a thought?