Glow Plug Controller

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I'm not convinced my glow plug system is working correctly. Details:

1982 BJ42 (12V electrics) imported to Rochester, NY where the temps are currently in the 30's (F).

When the engine is full cold, I turn the key backwards prior to starting. This activates the glow circuit - I can hear the relay click and see the battery voltage drop to ~10V (truck has a voltmeter).

The glow plug controller takes more than a minute to start glowing. When it does glow, it is so faint that I can barely see it. During the daytime I can't see it at all, no matter how long I glow. At night it's not much more very dim orange.

If I glow for 60 seconds or so, the truck starts fine, so that's how I've been working it. I saw a 24V BJ42 last fall that would glow like a flashlight!

Why doesn't my glow controller heat up very much?

I did pull the plugs for a visual inspection and to insure good contact. Champion part CH121, 8.5V, 8K. I've searched the archives and it seems 8.5V are the correct application here.

Thoughts?
 

RufusTheDufus

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Do you have something you can use to measure the resistance across the glow plugs? I suspect you have one or two plugs that are dead.

Does your engine start properly even with the faint glow indicator or does it run rough?
 

lostmarbles

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I'm not convinced my glow plug system is working correctly. Details:

1982 BJ42 (12V electrics) imported to Rochester, NY where the temps are currently in the 30's (F).

When the engine is full cold, I turn the key backwards prior to starting. This activates the glow circuit - I can hear the relay click and see the battery voltage drop to ~10V (truck has a voltmeter).

The glow plug controller takes more than a minute to start glowing. When it does glow, it is so faint that I can barely see it. During the daytime I can't see it at all, no matter how long I glow. At night it's not much more very dim orange.

If I glow for 60 seconds or so, the truck starts fine, so that's how I've been working it. I saw a 24V BJ42 last fall that would glow like a flashlight!

Why doesn't my glow controller heat up very much?

I did pull the plugs for a visual inspection and to insure good contact. Champion part CH121, 8.5V, 8K. I've searched the archives and it seems 8.5V are the correct application here.

Thoughts?
Hi there.

Well if your battery voltage drops down to around 10V while you're glowing, that suggests a high current draw off the battery which suggests to me that all 4 plugs are likely to be working properly.

And 8.5V plugs are the same as the ones I'm running, and AFAIK they are indeed correct for your 1982 manual-glow 12V BJ42 too.

So I'm puzzled likewise.

Perhaps you should just double-check that all your plugs are indeed working by removing the busbar and checking for "continuity" between each plug terminal and the engine-block? (Because if one plug isn't working your controller will certainly be reluctant to "glow".)

(And if you find one plug is open-circuited - replace the whole 4 as a set of course.)

Another test you could do is check the voltage at the busbar while glowing.

:cheers:

PS. Another possibility is: Perhaps someone has fitted a glow controller that is designed for a 6-cylinder diesel (6 x 8.5V plugs in parallel) instead of for a 4-cylinder diesel (4 x 8.5V plugs in parallel). That would certainly cause all your symptoms! (But probably an unlikely possibility.)
 
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Guys, thanks for the thoughts.

Looks like i have a bad glow plug. #1 is showing open, which would explain why the glow controller only glows dim after the longest glow cycle.

I was thinking about this last evening while trying to get to sleep and I started to suspect one or more plugs was bad. Your tips put me right on it.

I'm a first-time diesel owner so much of this is new to me.

Tom, I did read your thread last evening on compression testing and valve adjustment - very nice! I'll have to check my own parameters at some point in the near future too!

Off to the parts store to see if they can source me some new plugs...
 

RufusTheDufus

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The 8.5v plugs aren't easy to find. If you do find some please post where you go them. I could use a spare set.
 

Radd Cruisers

 
 
 
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Just a note here, it's VERY important to change all of your glow plugs at the same time with new units. It is a false economy to attempt to change just one at a time, as you will not get a uniform glow across all of the plugs and you will get a poor start up. Use a good quality brand like NGK.

If you have the right ones, your glow indicator should glow a nice red-orange colour in about 12 to 20 seconds (temp dependent). If it's glowing really brightly in a short period of time, you have the wrong glow plugs installed (too low voltage).

In North America (Canada) we had the manual glow system in the BJ42 up to the 1981 model year, and starting in 1982 they went to the super glow system.

As mentioned before, if you're getting a low system voltage when glowing, then you really need to look at your battery - it's probably not up to the task.

Continuity testing your glow plugs in a half-assed test at best. You really need to remove the glow plugs and power each one up and ensure that it glows quickly and brightly close to the tip. As glow plugs age and wear out, they will glow more slowly (relative to a new unit) and not glow well at the tip (glow about 5 or 8 mm further up the tip before actual tip lights up) - if this is the case, toss 'em and start again with new ones.



hth, John
 

Greg_B

 
 
 
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To add to what John said, here is a cut and paste from the part numbers thread for 12V manual system glow plugs:

Manual 12V

***Changes forthcoming***
 
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RufusTheDufus

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That info is misleading. It lead me to purchase 10.5 plugs when I should have bought 8.5 plugs. It's a 12v BJ42 (presumably from Australia) not a BJ60.
 

Greg_B

 
 
 
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That info is misleading. It lead me to purchase 10.5 plugs when I should have bought 8.5 plugs. It's a 12v BJ42 (presumably from Australia) not a BJ60.
That's good feedback that needs to get into the parts number thread. The data in the part number section is only as good as the feedback to the mods or OP's. When additions are needed, put the word out, so things can be tweaked, added, modified.

For clarification, is the correct Toyota part number 19850-68030 8.5v-12v? If so, shoot me brand name/part number data and I will add it to the post in the part number section.
 

RufusTheDufus

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I'll try to find the part number info and post it here. I'm running out the door.
 

Greg_B

 
 
 
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I'll try to find the part number info and post it here. I'm running out the door.
Good. If anyone has some older plugs laying around they may have the Denso number stamped as well. With the Denso number you can many times cross reference to other manufacturers.

For info's sake, you can run hotter or colder plugs in a manual system with no problems. It won't be "stock", however if you are aware how the system works...and you manage the time juice is running through them, it will be just fine. If you have an automatic system like the Toyota superglow, then keep with the stock plug (or other manufacturer match) numbers.
 

lostmarbles

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...For info's sake, you can run hotter or colder plugs in a manual system with no problems. It won't be "stock", however if you are aware how the system works...and you manage the time juice is running through them, it will be just fine.....................
Crickey. That statement could lead to all sorts of misunderstandings Greg!!!!!!!!

Unless you do something crazy like throwing away that marvellous glow controller then your plugs MUST match your glow controller.

If dkroth was to fit 6V plugs he would burn out his glow controller.

And if he was to fit 10.5V plugs his glow controller would take at least a minute to glow and he'd experience starting problems in cold weather.

But I know what you mean. Lots of people apparently fit so-called "Wilson Switches" and modify their wiring in all sorts of ways. Hence you often do see them running different plugs compared to what their vehicles were designed to run.

:cheers:
 

lostmarbles

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Good. If anyone has some older plugs laying around they may have the Denso number stamped as well. With the Denso number you can many times cross reference to other manufacturers.
8.5V plugs for a 12V cruiser are:
Toyota 19850-68030
NGK Y-128T
ND 067100-1350
APS 5013
EIKO GT208
JKT PT104
MAY PT104
 

Greg_B

 
 
 
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And if he was to fit 10.5V plugs his glow controller would take at least a minute to glow and he'd experience starting problems in cold weather.
Ya, I thought that might get some comments. :)

However, if you are stuck with no working plugs, have no access to "correct" plugs, and have some understanding that you "can" using something slightly off stock voltage spec numbers this just might get someone started and on their way. Just don't use a hotter plug and glow it for the same amount you normally would.

And yes, this is STRICTLY for manual glow systems, where the operator controls the amount of time sending current, ala the Wilson switch, home brew relay system or the early Toyota manual system.

Best course is, as you suggest...using the stock numbers.

Thanks for the other numbers, will be updating that info.
 
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All, thanks for your help with this.

I bought new NGK Y-128T 8.5V glow plugs from "aj4151" on eBay. The auction number is: 250050218573. Looks like that one is about to expire, but this guy runs an eBay store so he'll probably re-list. Search on the seller if you need to.

He's in the UK and I'm in New York State, USA. He shipped them registered air mail and it took 10 days for the package to arrive. Total cost for 4 plugs, shipped to the states was 38.86 GBP, or 56.81 USD after the conversion via Paypal. I don't know if that's a good price, but frankly I'm just glad to be able to start the truck easilly again.

For the record, the plugs that came out of my truck were Champion CH-121. That number isn't on the part number thread. Two different parts guys told me those aren't available in North America.

The new plugs are in the truck and they work great! The glow controller shines brightly after about 12-15 seconds in 40F weather.

Thanks again for the help guys!
 
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