Zd29s vs Zd9s...for the inquiring mind...

rreegg

Full Access Member
Joined
Feb 10, 2022
Posts
237
Reaction score
137
Location
Puget Sound
Dang, crazy to read these threads! There was one recently talking about the diesel rx plugs and how they're not great either (think poster had a tip break off/swell both in the truck and outside during a test). Glad to have gotten regular ol' zd9s a couple years when I replaced mine. But certainly will be on the lookout for shenanigans in the future.

Has anyone gotten a pack of zd29s where they have Beru stamped on them?
 

Black dawg

Registered User
Joined
Jan 9, 2006
Posts
3,995
Reaction score
703
Location
sw mt
Dang, crazy to read these threads! There was one recently talking about the diesel rx plugs and how they're not great either (think poster had a tip break off/swell both in the truck and outside during a test). Glad to have gotten regular ol' zd9s a couple years when I replaced mine. But certainly will be on the lookout for shenanigans in the future.

Has anyone gotten a pack of zd29s where they have Beru stamped on them?
Yes, the ones that I have gotten in the last 6 months have all been actual beru plugs.
 

captain720

Full Access Member
Joined
Feb 20, 2022
Posts
589
Reaction score
448
Location
Washington
Dang, crazy to read these threads! There was one recently talking about the diesel rx plugs and how they're not great either (think poster had a tip break off/swell both in the truck and outside during a test). Glad to have gotten regular ol' zd9s a couple years when I replaced mine. But certainly will be on the lookout for shenanigans in the future.

Has anyone gotten a pack of zd29s where they have Beru stamped on them?
Me too, ford dealership. A set was over $100
 

Black dawg

Registered User
Joined
Jan 9, 2006
Posts
3,995
Reaction score
703
Location
sw mt
I gave up on Beru and went with autolite dual coils.
What part number? I have not used an autolite of for any application that wasnt junk.

THinking back though it seems like I do remember one that was really slow but wouldnt burn out. Never tried in an engine though.
 
Last edited:

david85

Full Access Member
Joined
Feb 21, 2008
Posts
4,820
Reaction score
1,083
Location
Campbell River, B.C.
What part number? I have not used an autolite of for any application that wasnt junk.

THinking back though it seems like I do remember one that was really slow but wouldnt burn out. Never tried in an engine though.
I'm using Autolite 1115.

And yes, I've read the horror stories too over the years but I think those were for the direct replacement single coil plugs. These are dual coil plugs.

I tested each of them for 1min before putting them into the engine. The wire I used to power them started to melt but the plugs held up fine and did seem to self regulate. Heating time seems comparable to what I was getting from the Beru plugs before. The nice advantage is I can fire up the engine after 10 seconds or wait for 20 if its really cold outside and I want to heat soak the prechambers a bit longer. No need to cycle, just burn steady and then fire up.

I'm still reluctant to recommend autolite for everyone else, given the bad reputation we read about everywhere. But for me, the Beru's were just not holding up any more so I decided to try something else. I think there may be a bosch plug that is also dual coil but I don't know for sure.
 

Booyah45828

Full Access Member
Joined
May 2, 2017
Posts
878
Reaction score
670
Location
Ohio
1115 says it's a dual coil 11 volt plug. Buyers guide shows compatibility with 6.9 IDI and also the olds 350 diesel. It supposedly has a larger spade terminal, and a 10mm hex. This is probably sacrilege on here, but here's a pdf on autolite's plugs and some specs https://www.autolite.com/docs/default-source/product-documents/glow-2015-hi-res-a2556.pdf

With what I'm reading about the 1115 they seem similar to an acdelco 12g plug.

I originally tested 8 genuine 12g plugs with bad results. A couple exploded, a couple ballooned the tips, and not one worked after a few cycles. Supposedly the ceramic in them absorbs moisture sitting on the shelf, and that's why I got the results that I did. No idea if aftermarket versions have this issue.

I machined and used the acdelco 60g plug. They've been going strong for 5 or so years now. Here's a thread on 60g's https://www.oilburners.net/threads/custom-60g-glow-plugs.88914/

Supposedly bosch's 80034 is dual coil and fits without modification.
 

Black dawg

Registered User
Joined
Jan 9, 2006
Posts
3,995
Reaction score
703
Location
sw mt
Just recieved my order of ZD29 plugs. Bags and plugs are labeled zd29. Plug materials look identical to a zd9, same terminal crimp, but lettering on body is very slightly different and does not say beru on it. It looks to be just a change in part number, but I will test some and compare as closely as I can to a zd9.
 

captain720

Full Access Member
Joined
Feb 20, 2022
Posts
589
Reaction score
448
Location
Washington
When I put in my ZD29s they all read 0.7 ohmes now they all read 0 every single one of them, is that a problem?
 

david85

Full Access Member
Joined
Feb 21, 2008
Posts
4,820
Reaction score
1,083
Location
Campbell River, B.C.
Are all the leads still connected, or did you disconnect them before retesting?

EDIT: The reason I ask, is that if all the plugs are connected into the harness, they become parallel wired. This means the multimeter will "see" less resistance (more parallel circuits = lower resistance).

If you unplug the glow plugs first, now you would be testing them individually, so the multimiter would only "see" the plug you have the probe connected to (fewer parallel circuits = higher resistance).
 
Last edited:

captain720

Full Access Member
Joined
Feb 20, 2022
Posts
589
Reaction score
448
Location
Washington
Yes all tested individually, I am switching to CDDs controller so I have everything apart.
 

DaveBen

Supporting Member
Supporting Member
Joined
Sep 29, 2010
Posts
1,916
Reaction score
633
Location
Ukiah, Ca
If you touch each glow "pin" and connect your ground ( minus connector ) connector you should see about 1 ohm for each glow plug that are good. If you see zero ohms from the pin to the ground, the glow plug is junk. You MUST have the ohm meter set to the lowest number of ohms. Mine reads 200 ohms and less.
 

captain720

Full Access Member
Joined
Feb 20, 2022
Posts
589
Reaction score
448
Location
Washington
If you touch each glow "pin" and connect your ground ( minus connector ) connector you should see about 1 ohm for each glow plug that are good. If you see zero ohms from the pin to the ground, the glow plug is junk. You MUST have the ohm meter set to the lowest number of ohms. Mine reads 200 ohms and less.
Interesting, they seem to be working good, they pass the test light test fine and they pull down current when I push the button and it starts fine. Maybe my meter is struggling I’m not sure
 
Top