8 seconds. :-)

[johnrex62]

Is the glow plug cycle a Kioti thing? On my Kubota L3700SU I can hold the glow plugs on indefinitely without the light going off. I thought it was a manual activation approach, on my tractor at least.

I am not used to diesel engines and sometimes dont think to use them, but I also mostly mow and use the tractor when the outside temp is over 75 degrees. I haven't noticed any difference in starting with or without using the Glow plugs at the lower end temps I have worked in, almost instant starts either way.

 

[k0ua]

Is the glow plug cycle a Kioti thing? On my Kubota L3700SU I can hold the glow plugs on indefinitely without the light going off. I thought it was a manual activation approach, on my tractor at least.

I am not used to diesel engines and sometimes dont think to use them, but I also mostly mow and use the tractor when the outside temp is over 75 degrees. I haven't noticed any difference in starting with or without using the Glow plugs at the lower end temps I have worked in, almost instant starts either way.

John I don't believe our tractors have a timer to cycle the glowplugs.. It is "operator timed" 2 to 3 seconds for over 32degrees and so on.. Like you in the summer time sometimes I dont hit them at all if it is hot. But even down to 60 or so. it helps to hit them for the 2 or 3 seconds. makes for an instant start.

James K0UA

 

[ritcheyvs]

There are two types of Diesels: direct and indirect. Direct engines have no glow plug or prechamber and fuel is injected directly into the cylinder. Indirect motors have a prechamber with a glow plug and the injector sprays into the prechamber. NEVER use ether to try to start a prechamber motor. Prechamber motors tend to run smoother but at slightly lower efficiency, all other things being equal. Compression is the key to Diesel ignition; more compression means more temperature means faster ignition. But if the head/prechamber is cold, it can suck a lot of the heat out of the compressed air so the glow plug is needed to insure a hot zone to start ignition; longer glow actually warms the prechamber surface. Many new, low-hour Diesels will start fine with little or no glow if it's not too cold although they may smoke (white smoke from unburned fuel) at first. But older engines that have lost some compression (or have bad valve adjustment/timing) may not start at all without glow if cold. In this context cold means ambient and hot means near operating temperature, although very low ambient temps are worse. In the extreme, low ambient temps cause wax crystals to form in the fuel which can clog filters. This is worse of you have left-over summer fuel which has a higher "cloud point". Distributors try blend winter fuels by region to help avoid the "wax" problem but there's only so much you can do with #2 Diesel.

 

[dennis52]

There are two types of Diesels: direct and indirect. Direct engines have no glow plug or prechamber and fuel is injected directly into the cylinder. Indirect motors have a prechamber with a glow plug and the injector sprays into the prechamber. NEVER use ether to try to start a prechamber motor. Prechamber motors tend to run smoother but at slightly lower efficiency, all other things being equal. Compression is the key to Diesel ignition; more compression means more temperature means faster ignition. But if the head/prechamber is cold, it can suck a lot of the heat out of the compressed air so the glow plug is needed to insure a hot zone to start ignition; longer glow actually warms the prechamber surface. Many new, low-hour Diesels will start fine with little or no glow if it's not too cold although they may smoke (white smoke from unburned fuel) at first. But older engines that have lost some compression (or have bad valve adjustment/timing) may not start at all without glow if cold. In this context cold means ambient and hot means near operating temperature, although very low ambient temps are worse. In the extreme, low ambient temps cause wax crystals to form in the fuel which can clog filters. This is worse of you have left-over summer fuel which has a higher "cloud point". Distributors try blend winter fuels by region to help avoid the "wax" problem but there's only so much you can do with #2 Diesel.

My 45HP Kioti started fine, without having to use it's manual type glow plugs, when I bought it 10 months ago.
The tractor does operate in a sub tropical climate .
However after 200 hrs it is getting harder to start. I sometimes put the glow plugs on for up to20 seconds without getting it to turn over, then I'll try again and it's fine. The engine stop solenoid is definitely clicking on every time. Put new air and fuel filters in 30 hrs ago

From what's been posted it seems like it may not be a glow plug issue at all and I am thinking maybe a faulty relay ? Any ideas.

Finally, what is the maximum time I should leave the glow plugs on? The manual does not comment on this.

 

[kco]

Hey,
Let the glow plugs cycle themselves. They are temperature and timer controlled for optimum starting. Less smoke and longer starter life as has been mentioned. If it is extremely cold you can cycle more than once and also turn them on manually when first started to smooth out the coughing and smoke when cold.
Happy tractoring,
Dave G.
KiotiDave

I follow KiotiDave's procedure. If the engine is warm the glow plug will not come on and I start it right away. In weather around freezing or a little below, I let the glow plugs cycle, turn the key off/on so it cycles a second time, and then start it.

It's getting -5 to -10 (centigrade) these nights so I attached the electric cord that I had taken off for the summer back on the radiator hose heater. If it's cold I'll plug it in for 2 or 3 hrs before starting, and of course, still use cycle the glow plugs a couple of times. The other option is to hold it in the glow position for 15 seconds or so, but I prefer to use the automatic cycle a couple of times.

 

[kco]

My 45HP Kioti started fine, without having to use it's manual type glow plugs, when I bought it 10 months ago.
The tractor does operate in a sub tropical climate .
However after 200 hrs it is getting harder to start. I sometimes put the glow plugs on for up to20 seconds without getting it to turn over, then I'll try again and it's fine. The engine stop solenoid is definitely clicking on every time. Put new air and fuel filters in 30 hrs ago

From what's been posted it seems like it may not be a glow plug issue at all and I am thinking maybe a faulty relay ? Any ideas.

Finally, what is the maximum time I should leave the glow plugs on? The manual does not comment on this.

I think it must be some other issue. My DK35 has over 200 hrs and starts fine. The other day at about -5 C it started easily without glowing (I did not mean to skip that step). I've made the same mistake a few times around +5 or so and it starts instantly.

When you say it won't turn over, do you mean the starter does not turn the engine over the first time you try to start it? Or do you mean the starter works but the engine won't fire? If the former, it could be something to do with the safety stuff in the starting circuit. Such as the switches to make sure it is in Neutral, the clutch is in, and the PTO is off; or the relay they control.

I don't know the maximum time recommended for using glow plugs. My previous 30 year old Kubota L275 was hard to start and I had to use the glow plugs at least 60 seconds. In cold weather I would hold it on 90 seconds, it would fire but not start, glow again for 30 seconds, fire but not start, glow again, etc.. Perhaps the glow plugs were weak. I had a radiator hose heater that helped in cold weather and if it was quite cold (-30 C or so), I would sometimes tarp the engine and put an electric heater under it for a couple of hours. That made a big difference. But I'm sure you won't be doing that in Queensland.

 

[dennis52]

I think it must be some other issue. My DK35 has over 200 hrs and starts fine. The other day at about -5 C it started easily without glowing (I did not mean to skip that step). I've made the same mistake a few times around +5 or so and it starts instantly.

When you say it won't turn over, do you mean the starter does not turn the engine over the first time you try to start it? Or do you mean the starter works but the engine won't fire? If the former, it could be something to do with the safety stuff in the starting circuit. Such as the switches to make sure it is in Neutral, the clutch is in, and the PTO is off; or the relay they control.

I don't know the maximum time recommended for using glow plugs. My previous 30 year old Kubota L275 was hard to start and I had to use the glow plugs at least 60 seconds. In cold weather I would hold it on 90 seconds, it would fire but not start, glow again for 30 seconds, fire but not start, glow again, etc.. Perhaps the glow plugs were weak. I had a radiator hose heater that helped in cold weather and if it was quite cold (-30 C or so), I would sometimes tarp the engine and put an electric heater under it for a couple of hours. That made a big difference. But I'm sure you won't be doing that in Queensland.

Thanks kco.
The starter always works but the engine won't fire first time for a few weeks then seems to fire up first time again.
Like you , I was spoiled by having it start first time every time until recently.
I did have to replace my engine stop solenoid early on but when that malfunctions the engine will not receive any fuel and won't fire at all. I might try draining the fuel bowl.

How are the snowfalls in BC this season? My favourite place to ski.

 

[kco]

Thanks kco.
The starter always works but the engine won't fire first time for a few weeks then seems to fire up first time again.
Like you , I was spoiled by having it start first time every time until recently.
I did have to replace my engine stop solenoid early on but when that malfunctions the engine will not receive any fuel and won't fire at all. I might try draining the fuel bowl.

How are the snowfalls in BC this season? My favourite place to ski.

I have limited (i.e. almost zero) mechanic skills--but it does suggest a fuel problem. I think it should fire for your temperatures even if the glow plugs weren't operating.

I also encountered the engine stop solenoid problem a couple of times when the tractor was new. But each time it started after the initial failure and it hasn't happened since. So I wonder (and hope) if it was simply tight tolerances that fixed themselves with more operations.

Re: BC snow--I think it is far below normal for most of BC and definitely is below here (ski hill Silver Star, Vernon is 30 km south across the valley from me). I am in the hills midway between Vernon and Salmon Arm and we have a fraction (1/5 th?) of normal.

I think I put a curse on the area by purchasing a 75" snowblower this year. I have only been able to use it once on about 3" of snow.

But it may change. Yesterday the forecasts showed mainly dry and clear. Today they've changed it to snow/flurries/showers for the next seven days. So I'm hoping for that. Even without the blower I always enjoy lots of snow. It's prettier and healthier for the area.

Good luck with the starting problem.

And Merry Christmas.

 

[dennis52]

I have limited (i.e. almost zero) mechanic skills--but it does suggest a fuel problem. I think it should fire for your temperatures even if the glow plugs weren't operating.

I also encountered the engine stop solenoid problem a couple of times when the tractor was new. But each time it started after the initial failure and it hasn't happened since. So I wonder (and hope) if it was simply tight tolerances that fixed themselves with more operations.

Re: BC snow--I think it is far below normal for most of BC and definitely is below here (ski hill Silver Star, Vernon is 30 km south across the valley from me). I am in the hills midway between Vernon and Salmon Arm and we have a fraction (1/5 th?) of normal.

I think I put a curse on the area by purchasing a 75" snowblower this year. I have only been able to use it once on about 3" of snow.

But it may change. Yesterday the forecasts showed mainly dry and clear. Today they've changed it to snow/flurries/showers for the next seven days. So I'm hoping for that. Even without the blower I always enjoy lots of snow. It's prettier and healthier for the area.

Good luck with the starting problem.

And Merry Christmas.

Had a ball at Siver Star when I was a little younger. Bled the injector pump nut today and that seems to have sorted things out.

Merry Christmas to you.