kubota glow plug indicator not glowing/hard cold start

[stubbornrichard]

For some reason when i preheat, it dosn't glow but the glow plugs get warm but in no way hot as they should be, first i thought the connections so i cleaned all of them and same problem, the little coil does not glow even if i preheat for 40 seconds, it still takes about 3 tries to start the thing, i know its below freezing but i can't remember it ever being this hard. my fear is that the glow plugs are damaged (previous owner used starting fluid...ALOT), my other thought was the coil could need replacing. but these are just ideas, thanks for any help

 

[paulyny]

Ive been thru that before several times. If youve got meter start checking voltage. Start with the battery. Check the glow plugs for continuinity. I believe you should be getting 10.5v at the plug. Could also be the key switch too. Before you rip anything apart start poking around with a cheap multimeter. Worst case scenario in my opinion could be bad plugs. Maybe bad or dirty connections,bad ground etc.. Tractorsmart is who i use for my plugs. If you search old posts in the meantime you will get tons of info on the subject. Post back here with any results. What model Kubota is it?

 

[art]

It would be nice to know which model we are working with. I would take a guess that they haven't been right for a while.

With the thought that he could use either he had given up. I can't think of any Kubota engines that don't start when it is well below freezing on there own if the glow plugs are working.

You might also be fighting a loss in compression from the either if the use was as great as you say after you get them fixed.

 

[paulyny]

I bought a B8200 from a fellow that had trouble starting this machine for years. He drilled a hole in the air intake hose and glued in a 3/8 plastic tubing to spray ether into when he wanted to start it. It was hard starting and pre heat didnt work either. I simply changed the glow plugs and machine works as it should. Im still using it today. Dont use ether on a diesel!

 

[stubbornrichard]

Thanks for the ideas guys yea i was going to check them with a multimeter today, i had this problem with my other kubota the b7100 it turned out to be dirty connections but this problem is on my welding machine, it's a v1902 series motor, i shure hope the compression is good but once it starts it runs smoother than anything else i have and there is no smoke coming out of the stack just heat waves, i have a mobile welding buisness and use it every day so i have been letting this small problem go but now that its the winter it's really getting to be a problem, parts are easy to get for the engine but for some reason its hard to find specs on it, the dealer just told me "well its a good one" but had no idea on the output or other specs that i was obviously very curious about

 

[stubbornrichard]

Ok so i just came in from the engine, when i got out there i realized that i forgot how to properly use a multimeter so i put it on the 1k ohm and put the negative on the base of the plug and the positive on the little pointy tip and the dial sweeped across, this probably means nothing, so i thought i would ask how to properly set the meter and where to place the pins on the plug, but i did find out buy using the 1k ohm position that all the plugs are getting a connection, the good news is if i need new plugs they only cost about 56 bucks each i thought that they were over $100 each

 

[Lefty_Kubota]

are you checking the resistance with the glow plugs in or out of the engine?

 

[stubbornrichard]

i just checked them when they were still in the machine, the meter has a 15volt or 150 volt setting and i put it on the 15 volt one and when i hit the preheat switch the needle swept across like when it was on the ohms setting, so im guessing this means there getting power but its not really telling me if there properly working

 

[PILOON]

To properly check a glow plug (it is basically a resistor) you want to disconnect the wire to each one.

Select the lowest resistance scale on the meter (like 100 ohms) and read resistance from plug lug to engine block.

REading should be VERY low ohms (like under 50, and as low as 10).
If a reading on each-then OK.

If no ohms- then plug is open/burnt out.

Reading 12 volts at plug terminal is only indicating that power is getting there!

 

[Ford850]

Stubborn,
I pulled this from the Tractorsmart site:
"Other causes include defective glow plugs or low cranking speeds from a weak battery. The best way to check glow plugs is to yank 'em out and hook 'em to a battery (ground on the body, positive on the connection end.) If they glow red, they're OK. (Watch that you don't burn yourself!) Another problem with glow plugs is found in the connection wires between the plugs. These connections tend to corrode over time (just like battery cables). Clean them with some sandpaper before reinstalling to the glow plugs. If you don't want to test your glow plugs before replacing them, can I have your old ones? Glow plugs rarely go bad folks."