Glow plug questions

   / Glow plug questions #1  
H

handirifle

Veteran Member
Joined
Jul 2, 2010
Messages
1,713
Location
Central Coast of CA
Tractor
Massey Ferguson 1010
I'm new to diesels so bear with me.

My MF1010 uses the ign switch left position to activate the GP's. I was told to hold there about 20-30 seconds. It seems lately that is not enough. Today it took about 4 tries, holding 20-30sec each time to get it started.

Do glow plugs wear out?

I assume they're replacable, and if so, what's the approx cost?

Does anything else keep them from top performance?

Thanks.
 
   / Glow plug questions #3  
Yes, glow plugs do "wear out." On my old Peugeot 504D, I'd change one or two about every 8 months or so. Easiest check is to disconnect the wiring harness from the plugs and do a resistance check, from tip of plug where wire connects to ground. They can fail other ways, but they seem to fail "open" --infinite resistance-- most.

So far, my MF's plugs seem to be holding up OK (165hrs).
 
   / Glow plug questions #4  
If your glow plugs are old, they could be dirty. Sometimes taking them out, and cleaning them, (about a 15 minute job), will allow them to heat better, and faster.

If they are really loaded with soot, they can be difficult to pull out of the head. Wiggle them back and forth, while pulling it out.

If it is warm where you are, you should need little, or no glow plug time to fire it up.

Have you tried different throttle settings?

Each engine has it's own quirks. Sometimes, if you set the throttle up from idle a little, before cranking, it will start faster.

I have one that starts best when I advance the throttle to full, and back to about 25% while I crank it.
 
   / Glow plug questions
  • Thread Starter
#5  
Cool great responses, thanks. Looking at the engine, I see three wires that look like smallish spark plug wires that are attached with nuts so I assume these are the glow plugs?

Ouch, $16.95 each, good thing there's only three of them. I'm gonna have to go back to work. (retired) I am in the middle of building my workshop and a covered patio for our spa, and those two projects are sucking the life from our checkbook. :eek: That plus the fact that this dummy (yours truly) bought the wrong size tires for the front and had to buy a second set to keep from screwing up his tractor, that all adds up.

The tire issue will be OK since I have a neighbor whose Kubota uses that size (6-12's) and I will give them to him. He has a ride on trencher and a big Case 580 backhoe he will be doing some work for me with (building a seasonal pond). Seeing how it costs me about $165 a day to rent a walk behind trencher, the $200 tire boo boo won't be so bad after all.

Back on track.
I was about to "pull the trigger" last night and order an I&T manual, but having heard they are not super complete, I hesitate. Would that give info like glow plug resistance values?

Would the I&T be a good "for the mean time" manual until I can save for a full blown factory one?

On the plugs, what would I use to clean them if, hopefully, that's all they need, a wire brush or some solvent?

As far as warm here, it's usually somewhere in the low seventies or later in the day, mid to upper eighties. Once the tractor has been started and running it doesn't need anything but turning the ign switch and cranking it over.

I will try the different settings. I understand that, as I have an old 83 Honda XL600R motorcycle, and it is FAMOUS for being cranky on startup, either warm or cold. "Pull in the compression release, pull choke lever to full choke, ign off, cycle the kick starter about 8-10 times (no kidding), then ign switch on, cycle kick starter to just past top of compression cycle, release compression release and give it a serious kick." Nearly everytime I get it started in one or two kicks even if it has sat for 2 months. The hot startup is identical except only 5 "pre-kicks". The thing runs like a scalded dog once it's started. Now THAT is a quirky starting engine.

OK I will check and maybe pull the glow plugs as soon as I can. Hopefully a cleaning will do. If not then, 1950T, thanks for the link.
 
   / Glow plug questions #6  
I don't know what the prescribed way to clean the glow plugs is. I have always wiped them with a shop rag until they were clean.

If it is warm outside, even a cold engine start should not take a lot of effort, with, or without glow plugs. That's why I am thinking you need to try changing the throttle setting, and verify if it is possibly a fuel issue.

Low compression, low fuel pressure, or dirty injectors can also cause starting problems.
 
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   / Glow plug questions
  • Thread Starter
#9  
Well, today I pulled the glow plugs, claened them and re-installed. No change, unfortunately. Weird cause this seemd to happen all at once. Sure seems to run the same once started too.

I measured the plugs, both in and out of the engine. My ohm meter is digital, and shows a reading of 1.0 with leads apart (open circuit), and 0.00 with leads touched (complete continuity). When I measure all three glow plugs, they measured out to 0.00, complete continuity. Are there other tests to see if everything is working? How can I be sure they are actually powering up?

If I turn the switch to the glow plug position, I should read 12V correct? I wonder if somehow, they are not even getting powered up?
 
   / Glow plug questions #10  
Not sure what you're saying.... With the plug wire disconnected, you should be able to get a reading from the tip of the plug to ground --anywhere on the block-- in ohms, or a "beep" if you're checking continuity. If you get an open reading or no "beep," plug is burned out. If plugs are out of the engine, you'd check between the tip and the threads of the body. Perhaps I'm misunderstanding- wouldn't be the first time!:laughing:

If this is what you're getting, a voltage check --or a test light-- at the plugs, with key in correct position, would be next.

IF your 1010 is similar to my GC, I just noticed there isn't a relay-- just comes right off the starter switch ("main switch") on a black & yellow wire, terminals # 19 and #30. (Mine is the same, manually hold in left position for glow plugs.) Wiring diagram doesn't show any fuse in that circuit, either.

Keep at it- looks like it might be a pretty simple circuit, again, if it's the same as my GC.:thumbsup:
 
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