Resistance of glow plugs?

[TemporaryKubotaOwnerMark]

I've got a no-start condition. Fires a cylinder or two occasionally. Battery is good.

I have verified that I have good fuel flow to the injection pump. I'm getting 11.5 volts at the GP bar when the GPs are engaged, which seems a bit low, but I'm not sure. I did that test with a charger hooked to the battery just to be sure, and right after cleaning the battery terminals.

Can someone tell me what the voltage at the GPs should be while the GPs are on, and what the individual GP resistance should be?

 

[George2615]

Glow plugs should show a resistance anywhere from .1 - 6.0 ohms (more or less). Generally when glow plugs fail they either go fully open (no resistance) or fully closed (dead short).
A reading of 11.5 is probably correct if a glow plug is working. If working, the plug generates heat creating a load on the battery showing a lower reading than regular no load battery voltage. But just because your volt meter shows a load is being drawn doesn't mean all glow plugs are working. They need to be tested individually.

 

[thepumpguysc]

I've never like using a volt meter to tell me the condition of gp's and haven't been a fan of replacing just 1.
They all have the same time and voltage on them.. replace in sets and keep the spares for emergencys.
Just remove, apply battery voltage w/wire & alligator clips or battery charger or jump box.
+ on the top and - on the body.. DO NOT HOLD IN HAND.. They get or should get, firecracker red in SECONDS..
I normally just wait for the smoke and call it good.. no sense in burning yourself..
LET COOL, BEFORE HANDLING.

 

[The Fred]

Do you have an amp clamp? It's the most accurate way to test the glow plugs. Make sure your battery voltage open circuit (NO LOAD) is 12.6 or fully charged.

All 4 plugs together start drawing 80 amps cold then drop down as they warm up. If your battery is fully charged and your at 11.6 volts then sounds like the plugs are working.

Fred

 

[TemporaryKubotaOwnerMark]

Thanks, gentlemen. My mechanic (oldest son) checked the GPs today and got 1 ohm on all of them, so sounds like they are good. I have an amp clamp, and will get that test done just to be sure.

That points me in the direction of the injector pump. I know I have good flow to that point.

Any tips on that?

 

[The Fred]

There is a small external fuel pump on the side of the injection pump that transfers fuel to the main injector pump. Pull a line off it and crank the engien and be sure fuel flows through it.

After that crack one injector line then crank the engine over, fuel should spritz out of the line.

If no fuel repost.

Lots of posts about fueling issues.

Good luck, Fred

 

[art]

Have you replaced the fuel filters?

 

[thepumpguysc]

IF you have good flow TO the inlet on the inj. pump.. loosen the lines AT THE injectors.. and spin her over.. getting any fuel there??
IF NOT.. How does your machine shut off?? with the key or pull cable??
IF its w/ the key, you have to remove the shut-off solenoid and try again.. it may be the solenoid it bad or you have a blown fuse.
You can test the solenoid while its out of the engine.. IF it good and you STILL don't have any fuel coming out at the injectors.. its the pump.. Heres hoping for the best..

 

[TemporaryKubotaOwnerMark]

There is a small external fuel pump on the side of the injection pump that transfers fuel to the main injector pump. Pull a line off it and crank the engien and be sure fuel flows through it.

So there are three fuel pumps? One under the tractor, one on the side of the injection pump, and the injection pump?

After that crack one injector line then crank the engine over, fuel should spritz out of the line.

If no fuel repost.

Will do, and thanks.

Have you replaced the fuel filters?

Yes, both, and we have verified good fuel flow out of the second filter.

IF you have good flow TO the inlet on the inj. pump.. loosen the lines AT THE injectors.. and spin her over.. getting any fuel there??
IF NOT.. How does your machine shut off?? with the key or pull cable??
IF its w/ the key, you have to remove the shut-off solenoid and try again.. it may be the solenoid it bad or you have a blown fuse.
You can test the solenoid while its out of the engine.. IF it good and you STILL don't have any fuel coming out at the injectors.. its the pump.. Heres hoping for the best..

I had not thought of the solenoid! I will check that out. That certainly could be the problem. Where is it located?


I'm new to diesels. I know the theory, but I'm still gaining the hands-on part of it, so your help is much appreciated, gentlemen!

 

[David_Kb7uns]

Kubota tractors will have mechanical lift pump on side of engine or electric close to tank.

BXs have electric pump under floor board.

The BX tractors using the D902 or other 02 series engines have a keystop solenoid that only energizes to shut down. Usually is silver colored with rubber boot attached to top of injection pump fuel lever.

David