1.6TD starting problems ... glow plugs?

[dekhelia]

Recently my 86 1.6TD is impossible to start. I'm thinking it is probably the glow plugs (have ordered a new set), but was just wanting to ask a couple of questions about testing.

The glow plug relay seems to be working (can feel it actuate when ignition is turned on) and the yellow light on the dash illuminates and goes out after several seconds as it should; the fuse in the relay box is intact; the glow plug bases (well, on the plugs that are easy to touch) get warm when cranking, so I'm assuming they're getting current.

But: I've taken one of the plugs out and turned on the ignition, with the plug easily visible/touchable - and it doesn't get warm at all. I was under the impression that it should glow red-hot (hence the name, I guess) ... but nothing seems to happen.

Also, to eliminate any possible circuitry issues, is it ok to take a direct +IVE feed from the battery to the glow plug terminal, to check if it's working?

Many thanks for any thoughts on this. It's driving me nuts.

E D I T: one other question: is it true - think I read it on here or the Wiki - that no matter how far I tow the bus to try and get it to start, it won't if the glow plugs aren't working?

[jamesc76]

any diesel will start via towing just take a bit longer, yes you can pug a direct feed to the glow plugs to test um, but remember that the threaded bit must touch a good earth or nothing will happen!

[dekhelia]

Okeydoke, thanks for that. Didn't earth the plug when I took it out to test ... oops.

[dekhelia]

UPDATE: Crikey. What a difference new glow plugs make. Started first time, despite the fact that there can't have been much diesel in the pipes due to me disconnecting feeds from pump to each injector so as I could remove and then replace glow plugs. Incredible - made me wonder how long it had been since the last change.

Also, after having read various threads on here about replacing plugs in situ and what other items are best removed first to make the job easier: my experience was that there is no need to remove the injectors, but removing injector feed pipes from pump is a good idea for both accessing plug connections and for getting sufficient torque onto the bolts when reinstalling.

Vital, in terms of tools, is something long and thin with a magnetised end - otherwise getting the 8mm nuts back on to the bus bar connections is nigh-on impossible.

Have a little flexible LED lamp, too, so you can see what the hell you're doing. All in all, not that bad a job, really.