Glow Plugs

Hello,

I have a 1978 series 3 which has sat for a very long time, i'm just in the process of getting it ready for MOT and i have two questions of the glow plugs.

Firstly, how does the glow plug operation work? do they come on just with the ignition (i.e. stage 1) or is it a case of holding the key in a semi crank setting? there does not appear to be such a dedicated setting but do you hold it just off crank.

My engine has the plugs with the curled heater element. I was looking at new plugs and there appears to be glow plug conversions which use the straight type glow plug.

Is there any advantage to the straight type ones or is it best to stick with the original type?

Many Thanks

The old curly type are wired in series, the new type in parallel so you need to change the wiring slightly.
If its a diesel ignition switch there should be a preheat position or someone could have fitted a timed preheat thing.
Also possibly a separate preheat switch. It varies depending on its history of bodges.

A lamp should glow on the dash when plugs are live.[you may only be able to see it in low light though]