Self regulating glow plugs

[jonleroy2506]

Hey all

I just rigged up a manual switch for my gp's and went and burned em up. I guess I was heating the gp's too long cuz now they're all toast. Only 1 shows resistance, the others show exactly 0 resistance.

Anyways, my dad pointed me in the direction of self regulating glow plugs that you apparently can't burn up. He has em in his 82 chevy and says he can leave em on for 10 minutes and not cause any problems.

The issue is that I can't seem to find any self regulating glow plugs for the 7.3 motor. I've found em for the 6.9 tho. So could I just buy the 6.9 glow plugs and a wiring harness with the spade connectors? (It needs a new harness either way) or are there self regulating plugs for the 7.3? If so does anyone have a part number for them?

 

[chickenpot]

Sounds like a pita to change the harness out. Before i rigged up my manual switch i took a plug and hooked it up with jumper cables just to see how long it took to heat to red or so. Use that as a mental image while pressing the button.. 5-6 seconds or so

 

[jonleroy2506]

In theory that works. Not If you go to long though, lol. I just figure as long as I'm gonna have to do plugs again I might as well get the self regulators, if I can. The harness also has to be replaced because the connectors are quite beat up. So either way I'll be pulling the harness. I just need to know if the 6.9 plugs will work in the 7.3, or if there are self regulating plugs for the 7.3

 

[IDIBRONCO]

I don't believe that there are any self regulating glow plugs that have the bullet points on them. I'm running 6.9 Motorcraft glow plugs in my 7.3 and have been for over 4 years now. So yes they will work. FYI I have a manual control for my glow plugs and I only run them for 8 seconds at a time. Less if it's hot outside and the engine's cold.

 

[jonleroy2506]

Idibronco, are the motocraft plugs you use self regulating? Also, is there any chance you've got a part number for those? Everything I'm finding for 6.9 Motorcraft plugs look like the threads are a lot different than the 7.3 plugs

 

[IDIBRONCO]

They are ZD1A. They are the standard 6.9 glow plugs. They are not self regulating. The threads are exactly the same. From what little I know about them, the self regulating ones are made by AC Delco (for GM 6.2/6.5s) and, maybe, Bosch. They all use the spade type connector as far as I know on that too. Yes you can take 6.2/6.5 glow plugs and install them in a 6.9/7.3.

 

[jonleroy2506]

Thank that's a lot of help knowing that all of those motors have matching threads

 

[Austin86250]

The Bosch ones for sale for these motors are self regulating, but I’ve never had issues with my manual glow plugs
Like idi bronco says 8 seconds max if you need more wait a couple seconds but really you have fuel or compression issues if you need much more than that

 

[Booyah45828]

I've got the acdelco 60g plugs on a push button in the bus. They're self regulating from a 6.5 IIRC. Anyways I had to machine half the hex off the plug in order to get them to seat all the way down like they need to be. NBD with a lathe, but some don't have the tools like I do. I've heard of guys using a drill and bench grinder to remove the metal fwiw.

You might be tempted to use the 5.7 plug, 12g maybe? They're identical in size to the 6.9 and are self regulating. IMO they're junk, as all 8 that I tested exploded or burned out.

There was a bosch # that was mentioned as the right size that was dual coil and worked okay, I don't remember the number. Do a search on here, as it's been discussed before and my memory is hazy.

I'm not aware of any dual coil plugs with bullet connectors, but it's not difficult to swap the spade connectors on the harness, or do yourself a favor and get/build a new harness. Might not be a bad idea on 30+ year old wiring.

 

[KansasIDI]

I've got the acdelco 60g plugs on a push button in the bus. They're self regulating from a 6.5 IIRC. Anyways I had to machine half the hex off the plug in order to get them to seat all the way down like they need to be. NBD with a lathe, but some don't have the tools like I do. I've heard of guys using a drill and bench grinder to remove the metal fwiw.

You might be tempted to use the 5.7 plug, 12g maybe? They're identical in size to the 6.9 and are self regulating. IMO they're junk, as all 8 that I tested exploded or burned out.

There was a bosch # that was mentioned as the right size that was dual coil and worked okay, I don't remember the number. Do a search on here, as it's been discussed before and my memory is hazy.

I'm not aware of any dual coil plugs with bullet connectors, but it's not difficult to sway the spade connectors on the harness, or do yourself a favor and get/build a new harness. Might not be a bad idea on 30+ year old wiring.

80034 is that number

 

[Azidiguy]

80034 is that number

Those are self regualting as well?

 

[KansasIDI]

Those are self regualting as well?

To my knowledge. Might be best to have someone else verify that though, as I have given up on glow plugs and don’t know all the details, I’m rigging up an ether injection system, and lowered the compression a little bit, so it doesn’t ether lock so easily. Glow plugs are probably safer though. But I’m fairly confident the 80034 are self regulating.

 

[nelstomlinson]

I just bought some probably-genuine ZD28, supposed to be the replacement for discontinued ZD1. $17 each! I think the next round of replacements will be the Bosch for that truck. Probably-genuine ZD9s are only $10 each, but they use the bullet connectors...

The bullet connectors are a pain, the old originals are falling apart and I can't find replacements in the right size for the right size wire. I can find spade connectors, and self-regulating glow plugs sound a lot more forgiving.

 

[Black dawg]

bosch 80034

 

[IDIBRONCO]

I just bought some probably-genuine ZD28, supposed to be the replacement for discontinued ZD1. $17 each! I think the next round of replacements will be the Bosch for that truck.

At this rate, I need to start thinking about buying some Bosches for my Blue Truck.