Okay..... really off the wall question

[da SLUG man]

No it's the other 3 that are knackered. Less resistance means less heat generated. If they got much better at condicting they'd be a dead short and blow the fuse.

Cheers

don't they work by a heater coil? surely this is a coiled up piece of wire...
when it breaks down, you get no continuity.

[rich]

[Ems and Jim]

Thanks guys... all sorted yesterday morning.

Undid it all... wrote down the order of spacers, washers, connectors etc all fantastic !

Re-tested all the plugs, two completely dead and two perfect - its nice to have a whole engine worth of spares

Then I knocked the bl88dy black spacer off the top of the engine and lost it After a futile half hour of searching I gave up and made one from a touch up paint cap.... perfect fit !

My mate re-assebled whilst I made the coffee, then I came out and said
"Are they in this order Dave? Blue spacer, connectors, buzz bar, black (now red) spacer, washer, nut?"
"Ohhhh yusss" he says.....
POP goes the glow plug fuse

So, having bent the two ends of the blown fuse together and put every thing in the order that I said in the first place everything is brilliant... No stuttering, no coughing and no smoke in the morning. She fires up straightaway and runs on all four at the first turn of the key

Thanks for the patience, advice and adding to the general confusion that is my life