Glow plug system diagnostics

TWeatherford

Full Access Member
Joined
Oct 6, 2008
Posts
1,172
Reaction score
10
Location
Flagstaff, AZ
Wow, I'm on a roll, posted three new threads in the last few minutes.

Today I set out to diagnose my glowplug system. I am not starting very well, at 32 degrees it takes about 20-30 seconds of cranking and I'm confident it won't fire colder than that. The glow plug light never stays on for more than 10 seconds, I'm thinking about replacing it with a push button, and probably will in the future.

So I disconnected this plug on the driver side

You must be registered for see images attach


it looks like it goes to all the glowplugs. There are ten "used" plugs in it and two "unused." I got an open reading (between the plug and battery ground) on all of them except the two next to the unused plugs, which read something like 8.5 and 4.1. So thats a little wierd. I may be way off base in doing a test like this here, but its what I did on my old Mercedes diesel. Based on that, I have all bad plugs, wires, or both, however that might not be right since I am starting and have a feeling I might not without any assistance from the glowplug system.

So I moved on to the plugs themselves. Between battery ground and the top of the plugs the front four read something like .1 or maybe .2, very low, so I'm thinking they're good. The back two on the driver side open or very high, can't remember which, so they're definitely bad. I didn't mess with the back to on the passenger side because they were so hard to get to. If I go to replace them I'll probably just remove the aircleaner and injector lines, anything special to know about that? Like one time use orings or crush washers on the injector lines?

The plugs that plug into the glowplugs were also pretty brittle, I don't think they're very good, so I may end up having to replace that wiring harness. I've read the horror stories about swollen tips breaking off in the motor, so I was thinking I could go ahead and take the time to put each cylinder to TDC for that plug, to save myself hopefully if I do break one off. I only have a sort of basic idea whats going on there, so some advice on how to do that would be great. I've looked but I don't think there's a tutorial anywhere.

And thanks a lot in advance. This forum is a great asset to owning older trucks like mine.
 

TWeatherford

Full Access Member
Joined
Oct 6, 2008
Posts
1,172
Reaction score
10
Location
Flagstaff, AZ
Ok, did some homework, problem was I was on someone else's computer so wasn't able to save any of the pages I was on for future reference.

I ordered 8 new Beru's, for just under $9 each from http://www.fleetsource.com/176397_Bord_Warner_BERU_Glow_Plug_1988_1994_Fo_p/176397.htm which is the best price I've found. I'm going to set each cylinder to TDC before I try to remove the respective plugs. I read somewhere which cylinders would be at TDC for each 1/4 turn of the engine. Can someone enlighten me? How about the injectors/lines? Are there any special seals I should have on hand? If I get too frustrated I think I'll just pull the lines, seems it would be a lot easier to get the plugs out especially if they're being stubborn, but don't want to have fuel squirting everywhere if I needed some o-ring replaced. I guess I'll give the plugs a preliminary soak in pb blaster right now, so they've got some time to really soak before I try this.
 

GenLightening

Yeah, it's a CHEVY!
Joined
Oct 24, 2006
Posts
1,917
Reaction score
1
Location
Pukalani, Hawaii
Wasn't there a thread recently where someone bought those and they were actually the BW plugs and not Beru? And if all you're doing is changing the GPs, then you shouldn't have to touch the injectors and lines, which is a good thing.
 

TWeatherford

Full Access Member
Joined
Oct 6, 2008
Posts
1,172
Reaction score
10
Location
Flagstaff, AZ
Wasn't there a thread recently where someone bought those and they were actually the BW plugs and not Beru? And if all you're doing is changing the GPs, then you shouldn't have to touch the injectors and lines, which is a good thing.

I hope not, uh, I thought they were the same thing? Maybe I can call and cancel my order.
 

Latest posts

Forum statistics

Threads
93,029
Posts
1,156,233
Members
26,618
Latest member
Nathanelliott44

Members online

Top