Changing the glow plugs in '92 L300 Exceed

[Delicalicious]

Hi all

Just a quick run-down on changing the glow plugs, since I went through a bit of a learning curve to do this (my first time).
I was having problems starting over the last week - the first time I thought just the shifter was not completely set into park, but the second time, just one glow plug "click" rather than the usual two, and totally unstartable. Battery was fine (at least lights/stereo were coming on as usual) so I assumed it was the glow plugs.

Of course, this being 1) my first diesel vehicle and 2) my precious Deli, I'm always uber-paranoid about f$%&ing something up.
First, I tested the readings on the battery and plugs with a digital voltmeter (the pos pointer of the meter on the pos terminal of the battery, the neg pointer on the glow plug tip). I didn't think until later to check the bus bar as well. The readings were all good (~12.38V) but I wanted to see if something was up anyway.

These are the tops of the glow plugs (I've already removed the wiring and plate (the bus bar) on this photo).

IMG_1319.jpg (58.01 KiB) Viewed 5216 times

Here's the photo with the plate and wiring:

IMG_1320.jpg (48.02 KiB) Viewed 5216 times

The first glow plug I pulled out. There's some oil on it which bothers me... is this normal? (it doesn't seem like it should be) Does it suggest an oil pressure problem?

IMG_1314.jpg (48.08 KiB) Viewed 5216 times

Here are three of the four after cleaning with a rag (I replaced the first one, then realized I should compare all four):

IMG_1315.jpg (58.41 KiB) Viewed 5216 times

*****
After cleaning and replacing all the plugs, I tested the connections again.

On the battery: 12.38 V
On each plug: 12.36-12.37 V
Between each plug and the bus bar, with the key turned on: 12.36V

And it fired right up on the first try. So I guess the plugs between fouled with soot/oil was the problem. If anyone wants to comment on this that would be helpful.

Wanted to add my little contribution to the Delica community for return on all of the questions I've been able to answer from reading old threads. Many thanks!

- S

[frige]

Hi there,
Were you using a special wrench when you were fixing the glow plugs back after cleaning?
Were you not afraid to overturn the plugs?
Could worn out (or just too old) glow plugs be a reason for eating the battery's power down below acceptable level after which starting up the van is impossible?
Thanks for your answers.

[Firesong]

Could also have been the connection at some point in the mix. Sometimes all it takes is taking them out. Stirring the pot ;) and thinks work. Also called..got lucky

[sealica]

I'm trying to remove my glow plugs to test them because the amount of smoke when starting the van has suddenly increased tenfold to the point of almost not starting below freezing; previously I've started the van many times below freezing ... smoky and rough yes, but not like this.

Problem is I feel like an idiot, but the little nut atop the electrical connector to the glow plug plate (third glow plug from front of van) is very difficult to loosen and it appears I'm just stripping it ...

6mm doesn't fit (too small), 7mm doesn't seem to fit, and 8mm is too big ...

The connector doesn't seem straight as pictured and there is a somewhat sharp upwards bend in the metal connector perhaps interfering with the removal of said nut ... there's no chance it's SAE rather than metric or something crazy like that or 6.5mm???

I also share the poster's concerns with oily glowplugs. There is also a ton of dirt, dust and grime in the area around the glowplug - will this fall into the engine if I don't get the area clean - especially the particulates?

[Growlerbearnz]

They should be 7mm nuts, but if it's not genuine Mitsubishi all bets are off. it might have been replaced with an Imperial nut at some stage, and that's why it's stripping?

[sealica]

OK. Well I'm pretty certain I figured out my problem after testing my glow plugs with some jumper cables.

I had two plugs functional, and two plugs not. Unfortunately I connected the positive clamp to the wrong area of the glow plug and got some sparks and welding action and damaged the ceramic tip (glad I was wearing safety glasses/gloves!!). Newbie mistakes, but I'm learning! Re-tested the damaged plug properly and it was one of the two functional ones, but going to replace it anyways to avoid broken bits in the engine.

I'm glad I removed the old plugs prior to buying new ones since I have a 1992 L300 P35W which would've led me to the 6.2V according to most of what I read online. Coombs website says "Fits upto 1993 model years" regarding the 6V plug. I think it's a bit nuanced in that there is a crossover year (1992) where both kinds of plugs are used in vans with different systems; "auto glow system" and "super quick glow system".

My old plugs say: GP Y722JS 11V OA3 so I went with the 11v >93 plugs after calling a local shop who were unfortunately out-of-stock on the needed plug.

Now to source a new 7mm (M4?) nut because I removed the last one with vicegrips ...

PS - Is there a dash light for the glow plugs?? I've never had one ..