Diesel glow plug question (1 Viewer)

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Aug 29, 2007
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Los Gatos, CA
I have a 1983 RHD BJ42 from Australia. I've had it about 14 years, and every few years when it becomes difficult to start when it's getting down into the 30 degree range, the rest of the time no problem. I pull the blow plug and usually 3 out of four have the tips burned off and the wire glow element is showing. In warmer weather I guess the one working glow plug is enough to get it started and the other cylinders kick in when the engine is starting. I was told by one of the techs at Specter Off Road when I was buying a new set of glow plugs, and he saw that I'd bought a set before, that this isn't normal. If that's true, what is causing it, and most importantly, what can I do to fix the issue?

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holy jeezus!
Id definitely do something about that as that metal is ending up in the cylinder before being ejected
First thing id check is the glow voltage is correct for your truck, are they 12v glows going in a 24 volt truck or something?
I think ive also read that advanced injection timing with increased fuel can lead to this, but not 100% sure on that.
 
Are you using a Wilson switch?
 
Stock 1983 BJ42 from Australia would be 12V Super Glow system. The stock system glow plugs are 6.5(?)V.

Any changes to the stock system and all bets are off and we’d need more information to help you.

Look for a thread by @lostmarbles for everything you wanted to know about Glow Plugs and then some.

 
holy jeezus!
Id definitely do something about that as that metal is ending up in the cylinder before being ejected
First thing id check is the glow voltage is correct for your truck, are they 12v glows going in a 24 volt truck or something?
I think ive also read that advanced injection timing with increased fuel can lead to this, but not 100% sure on that.
It's a 12 volt system. I'll look into advanced injection timing. Thanks.
 
Stock 1983 BJ42 from Australia would be 12V Super Glow system. The stock system glow plugs are 6.5(?)V.

Any changes to the stock system and all bets are off and we’d need more information to help you.

Look for a thread by @lostmarbles for everything you wanted to know about Glow Plugs and then some.

As far as I know and can tell, it's a totally stock truck and ignition system. I'll try to find @lostmarbles. Thanks
 
If you are handy with a multimeter, you could put a voltmeter on the glow bus bar and see what voltage you are getting. It looks like you're getting too high a voltage, for too long.. It should only be full voltage for a few seconds then step down for the remainder of the time that voltage is going to the bus bar.. I saw a post you made last year about the same problem and there was good advice given to you then. Did you lose track of that thread?
 
As far as I know and can tell, it's a totally stock truck and ignition system. I'll try to find @lostmarbles. Thanks
The thread is there, but sadly Tom is no longer on the forum. Several years ago he was in a wreck in his BJ40 at highway speeds IIRC. He was ok but the Cruiser was totaled.
 
they are cooked!!! too much something, I'd guess too much voltage for too long. Look on your glow plugs, they should say what voltage (prob 6.5v) they are and then go the next voltage up. Yep lostmarbles did a comprehensive. There is a surprising variety of same size glow plugs with different voltages.

Off my head there is 6.5, 8, 11, 11.5v etc for the same size glow.

you are almost better off with a higher voltage glow plug and glow for longer rather than cook them. How long are they lasting you?, they can last a long time, like years, without changing them if the right ones. They should never look like that, they won't work.

I knew a sparky who used old glow plugs as soldering irons.

Highly recommend a wilson switch, count longer during winter, shorter for summer. Watch an ebay aftermarket cig lighter digital volt meter, initial drop whilst glowing then the volts go back up when the glows are hot, then turn for ignition. Better than superglow I reckon, got rid of my superglow. With a wilson switch you control how much you glow for.

The superglow is a simple computer, but electrical is often the first to go in old cars.

You can find wilson switch on here.

Unless indeed, it is somehow fuel related. If it was over fueling all the time, other things would be getting hot in your engine too I would imagine, injector nozzles, precups, piston heads...

If everything is tickety boo as far as fuel, you simply have the wrong glows, or you superglow is playing up.
 
they are cooked!!! too much something, I'd guess too much voltage for too long. Look on your glow plugs, they should say what voltage (prob 6.5v) they are and then go the next voltage up. Yep lostmarbles did a comprehensive. There is a surprising variety of same size glow plugs with different voltages.

Off my head there is 6.5, 8, 11, 11.5v etc for the same size glow.

you are almost better off with a higher voltage glow plug and glow for longer rather than cook them. How long are they lasting you?, they can last a long time, like years, without changing them if the right ones. They should never look like that, they won't work.

I knew a sparky who used old glow plugs as soldering irons.

Highly recommend a wilson switch, count longer during winter, shorter for summer. Watch an ebay aftermarket cig lighter digital volt meter, initial drop whilst glowing then the volts go back up when the glows are hot, then turn for ignition. Better than superglow I reckon, got rid of my superglow. With a wilson switch you control how much you glow for.

The superglow is a simple computer, but electrical is often the first to go in old cars.

You can find wilson switch on here.

Unless indeed, it is somehow fuel related. If it was over fueling all the time, other things would be getting hot in your engine too I would imagine, injector nozzles, precups, piston heads...

If everything is tickety boo as far as fuel, you simply have the wrong glows, or you superglow is playing up.
Here is an update. When I last posted this in December, and put in new glow plugs. It became difficult to start again so I pulled the new glow plugs and they are already burned out like the last photo posted. That was only 3 months. Obviously something is wrong. I checked the bus bar when I turn on the key, and it's 8.4 volts. The glow plugs I bought from SOR are rated for 8.5 volts, so they aren't gettin too much juice. I also tested to make sure the power was shutting off. When I start the engine the power stays on for about 20 seconds then shuts off, so they aren't being continuous power and burning them out. I'm baffled.
 
Yea that's not normal, they're toast!
Does it run well normally?
Could be pump timing??
Maybe you only run very short trips at low speed for a long time and coked it up??
 
Really tricky to diagnose electrical. All contacts, wires and relays should be inspected. It still is possible that 8.5v that you measure is too much for your 8.5v glows, they are exposed to the max they can take for 20 secs every time you glow. Which maybe why they burn out.
It is an old car, who knows if a pvo did something, copper corrodes, a superglow system is not as fail safe as a wilson switch.

For example, my superglow ran on 6v glows from 1988. I pulled out my superglow relay (electrical relay is over 30yrs, chances it is not tip top) and bypassed the relay with a wilson switch. Installed 11.5v glows to avoid burning them out. When I hold the button down, I watch the $3 ebay cig lighter voltmeter. It drops from 12.6-7v to 11v (12.5v to 10.4v if the battery is not healthy) as the glows drink and warm. I count to about 16, sometimes more during winter less during summer whilst I watch the volts. The volts climb back to 11.3v (little less if battery is old) which is a sign to me that the glows have stopped drinking and are warm, I kick over, starts every time. The glows are several years old, the last time I changed them, the old ones looked close to unused.

Using higher voltage glows takes me 12 seconds longer-ish than a superglow. But as I am watching the voltage I am ensuring that I do not cook my glows, by kicking over exactly when they are warm. It is fail safe.


Further more, I use an engine guard temp gauge , a thermo couple which bolts to the head. It is really accurate. After I have already run the engine, driven wherever and switched off, naturally the engine cools down. A glance at that reading tells me if I need to glow again if below, say, 40c-ish.

So the combination of reading the volts, counting the time and monitoring the temp , I act as the superglow.

There are two very simple computers in your car. The superglow and the edic relay. It is most common that they both fail over 30 + years, which is actually pretty good for electricals.

The older b engine had a little coil which heated up and glowed in cab as one manually glowed by counting and watching the coil.

I know a young fella here in melbourne, who is making a replacement for the superglow, it shall have an inbuilt wilson switch, if ever, needed. He is already making and supplying edic control boards already and can be found on facebook, he is on ih8mud somewhere too. The 3b and 2h have the same electrical setup virtually.

I'll try to get him to chime in, seeming you have the 12v system. He is working towards 24v systems too.
 
My bet is you've got a glow relay intermittently sticking on. Like a starter solenoid sticking, it might not happen every time, but it only has to stick on one time out of 100 to torch your glow plugs. Change your glow relay over and see what happens. I'll bet three months from now your plugs are good.
 
Yea that's not normal, they're toast!
Does it run well normally?
Could be pump timing??
Maybe you only run very short trips at low speed for a long time and coked it up??
Yes it runs well normally. Virtually all my drives have some length as I live 20 mins from town and other errands are longer. I live up in the Santa Cruz Mts, so going home it gets a good workout going up to 2000' Being 90 hp diesel I end up in 3rd gear at 2800 rpms to keep it at 45 mph. I've also driven it several times to Lake Tahoe, 4 hour + drive, and again this April taking it on a 8-10 hour drive to Death Valley with the 4 wheel drive club for a multi-day overland trip. I'll google "pump timing" to see how to check that out.
 
Yes it runs well normally. Virtually all my drives have some length as I live 20 mins from town and other errands are longer. I live up in the Santa Cruz Mts, so going home it gets a good workout going up to 2000' Being 90 hp diesel I end up in 3rd gear at 2800 rpms to keep it at 45 mph. I've also driven it several times to Lake Tahoe, 4 hour + drive, and again this April taking it on a 8-10 hour drive to Death Valley with the 4 wheel drive club for a multi-day overland trip. I'll google "pump timing" to see how to check that out.
You'll need a specific tool to check your timing. I have no idea about your engine, but generally you need a runout gauge with a specific adapter. You're measuring fractions of a MM in piston movement inside the pump. Broadly, if it gives a little white smoke on startup, and then the exhaust is clear when it idles after warmup, but gives a little black smoke at WOT, it's pretty ok. But you should still check it.
 
I agree with @Nemesis1207. That sounds like a sticking glow plug relay. It only needs to happen once and zap. Install a new relay and see -- they aren't expensive. Best of luck.
 

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