I.D'ing brand of existing glow plugs?

[pybyr]

I'm new to being an owner of an IDI-- and mine is not too happy to start in cold temps (20F and down), so I've been reading the various tech articles and threads about glow plugs. My 1989 has very low miles (13,500) and has had very good care (it was a fire truck, serviced by a reputable local service shop). Glow plug controller looks visibly newer than the other wiring, and the glow plugs themselves look as if they are younger than the engine (quite clean, wrench marks).

How do I tell what make and type of glow plugs are in it?

Thanks!

 

[jcarr]

only way i know is to pull them and read what is stamped in the side of them.