I have a 1978 Toyota “B”. It’s been totally rebuilt. 5 miles on it. Case, Head, valves, cylinders liners, pistons, injector pump, injectors all rebuilt. After test driving I continually (3X) have a burnt or broken glow plug on the number 1 cylinder. I’ve removed the head each time to inspect. No damage, yet. The plugs all break at the exact same spot. (See pictures below) I’ve swapped injectors thinking the injectors were spaying the plug. Not the case as it stayed with the number 1 cylinder. My head gasket shows damage were the pre-combustion chamber overlaps the edge of the cylinder. Could movement from the pre-cup cause this? I did have the head decked. Any help would be greatly appreciated.
Help! 3 broke/burnt Glow plugs from the same cylinders.
- Thread starter Windycity
- Start date
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bummer
Can you share a picture of the cylinder’s head (underneath), electrical connection of the glow plugs (bus bar/ isolator etc)
Details of yours glow plug setup.
Details of the glow plug.
The damage on the cyl head is probably from the glow plug overheating…
Can you share a picture of the cylinder’s head (underneath), electrical connection of the glow plugs (bus bar/ isolator etc)
Details of yours glow plug setup.
Details of the glow plug.
The damage on the cyl head is probably from the glow plug overheating…
I hope you have a 12V system, they are 10.5 V glow plugs.
- Thread starter
- #4
Thanks for the reply. I’ll send pictures in the morning.
I do have it set-up for 12V. Thanks.
sorry, i re-read your post. This is a very interesting problem.
I have never seen a glow plug fail like that, and so uniformly across three of different brands.
I have never seen a glow plug fail like that, and so uniformly across three of different brands.
Thats super weird. Is it possible through some wiring error that that the glow voltage is stuck on permanently in that plug? The plug on the far right looks overheated by its internal filament, not from external heat.
- Thread starter
- #7
Here are more pictures. I have a simple “Wilson switch” to a glow plug relay set-up. I don’t believe that the alternator could over power it, but I tried to troubleshoot it anyhow.
-I did a drip test of my injection pump ( just rebuilt). It is about 6 degrees retarded. I’m starting to think that may be causing my problems. Does that sound plausible?
- Thread starter
- #9
It’s hard to tell. I’ve done some further investigation. Please look over my latest post and let me know what you think.
- Thread starter
- #10
Here are the basics of my 12V glow system operation manually through a “Wilson switch).
I've had glow plug issues in the past when the glow plug relay would occasionally get stuck in the "on" position. This would quickly burn out all 6 of my glow plugs. I repaired the relay and also, for backup, installed a buzzer to indicate when there was power to the glow plug busbar. I also installed a busbar cut-off switch on the dash to throw if the buzzer stayed on too long. (I still have the Super-Glow system working, so it does all the glowing automagically)
Form what I can see from your pictures, all your glow plugs should burn out if the relay sticks on, but it might give you something to think about as you look at your system... Is it possible your first glow plug is somehow wired in series, so when it burns out, the other ones get de-powered? From the pictures, it doesn't look like it, it looks like its properly wired in parallel, but I'm also not looking at it and poking it with a multimeter...
Good luck. It's frustrating as hell burning out expensive glow plugs over and over- at least they aren't going 6 at a time, like mine were...
Form what I can see from your pictures, all your glow plugs should burn out if the relay sticks on, but it might give you something to think about as you look at your system... Is it possible your first glow plug is somehow wired in series, so when it burns out, the other ones get de-powered? From the pictures, it doesn't look like it, it looks like its properly wired in parallel, but I'm also not looking at it and poking it with a multimeter...
Good luck. It's frustrating as hell burning out expensive glow plugs over and over- at least they aren't going 6 at a time, like mine were...
- Thread starter
- #12
Here’s the latest. I went to time the Injection pump, and it looks like the pump was put on, on the exhaust stroke, not the compression. Probably had major detonation issues. Btw, that was done by a professional engine shop, not me!! Hopefully that’s the problem
Yikes.
Really? How did it run?
