New MX5100 smokes/coughs on startup

[MHarryE]

What do you mean by required? Like they wouldnt start without the plugs?

My 2005 MX5000 starts fine at 24F with no pre-heat. I even started it cold down to 10F once out of curiosity. 20F is my normal cut-off point on using the glow plugs.

Two would have started and run roughly without glow plugs but that does add stress to the engine and why do that if I don't have to. The third needs glow plugs when cold even on a 70 degree day.

Today I had to start the combine in my avatar to put it in its proper storage position as we stow things for winter. It has a 225 HP direct injected 7.7 liter engine. Thirty degrees, took about ten seconds cranking before starting with a lot of smoke and rough running. No glow plugs on the engine but it does have built in ether starting aid. Only thing is the can installed is empty because we don't use it in below freezing temps - except for something like this.

 

[cmikewil]

to see if your glow plugs are having an effect Turn the key and start with no delay, note your smoke and cough..... next day similar temp cycle your glow plugs twice to see if it starts the same. I'm betting its normal for this type tractor. good Luck

When you say cycle your glow plugs twice, what do you mean? The owner's manual says to hit the glow plugs for 3 seconds (+/-) at 40 degrees (longer when it's colder), and then turn the key to start. Are you saying to go for 6 seconds before starting?

Sorry to appear clueless, but...I might just be!


And thanks, Bucktaker!

 

[bucktaker]

on my L5740 I have a dash indicator thingie it stays on based longer based on temps that indicates to me the cycle time for glow plugs. Do you have such a indicator? all my diesel trucks had such a "wait to start" indicator.

But yes leave the glow plugs on one or two or more cycles to see if your starting symptoms change

 

[MHarryE]

Some engines have a temperature sensitive timer so power to the glow plugs is cut off and the light goes out after the time set in its memory. Cycling them twice would be switching off after the light goes out, then turning it back on to cycle again.

On some the glow plug light is the only thing on the timer so the glow plugs remain active after the light goes out. The light going out is just an indication to the operator it is time to start cranking.

My mini-excavator glow plugs work by turning the key backwards. The glow plug indicator light comes on and the glow plugs are heating as long as you hold the key. After using it for awhile I kind of have an idea of how long I need to heat the glow plugs. On really cold starts the engine may die after running for a few seconds and I will need to repeat the glow plug heating. It doesn't do any good to heat the plugs longer in the first place - the cold air going into the combustion chamber cools them even after heating.

My Kubota RTV glow plug light stays lit even after the glow plugs shut off. I can tell when the glow plug power is cut by the click of a relay. Hear the click - its time to start.

 

[kuboman]

My l5740 smokes and farts for 6-7 seconds on every cold start whether it is 70 above or 30*. These new epa engines pollute more in the first 10 seconds than my old one does in a hole day.

 

[cmikewil]

on my L5740 I have a dash indicator thingie it stays on based longer based on temps that indicates to me the cycle time for glow plugs. Do you have such a indicator? all my diesel trucks had such a "wait to start" indicator.

But yes leave the glow plugs on one or two or more cycles to see if your starting symptoms change

Gotcha. No, I don't believe the MX5100 is set up the same. You turn the key counterclockwise for glow, and then clockwise to start. So, you cycle the glow plugs according to what the owners manual suggests depending on temperature - or according to what TBN list members tell you.

So, I'll try what I'm told here, that being to increase the time. Will let you know. If things don't get better, I may give the dealer a call to see what he says.

Incidentally, my farm is approximately 30 miles from where I live, so I can't just run out and start the thing whenever I want. Heck of a thing not being able to get to your new tractor at a moments notice!

 

[Ken45101]

Gotcha. No, I don't believe the MX5100 is set up the same. You turn the key counterclockwise for glow, and then clockwise to start.

You are probably right but double check your manual. I have a half dozen pieces of Kubota equipment and EVERY one is turn CLOCKWISE to the first notch for the preheat.

The MX5100 could be different (and you are probably correct) but double check that.

Ken

 

[Bluegill2]

You are probably right but double check your manual. I have a half dozen pieces of Kubota equipment and EVERY one is turn CLOCKWISE to the first notch for the preheat.

The MX5100 could be different (and you are probably correct) but double check that.

Ken

Both my Kubotas, L3750, L3800 turn counter clockwise for glow plugs, hold as long as you want, then clockwise to start.

 

[Herkypilot]

Mine coughs and sputters too at start up. I just let it warm up for a couple of minutes. It's a diesel - I expect it when it's colder.

HP

 

[indianaEPH]

I would say it is normal. Mine does the same.