LB2204 Cold Starting

RandR10 · Jan 25, 2022

So I've been having trouble cold starting the tractor even after the rebuild. It'll fire right away after a glow plug cycle but run really rough for about 30 seconds before it smooths out and runs properly. Very smoky exhaust before it smooths out too. Doesn't seem to matter much what the outside temp is, it always does the same thing if it's been sitting awhile. Sometimes it'll stall a couple times and I'll have to re-cycle the glow plugs to get it to rev up and smooth out. Thereafter it runs like a top and has plenty of power. If I shut it off and restart while it's still warm, it fires right up and runs smooth right away. This leads me to look at glow plugs.

So I took a look at my glow plugs today and I'm getting just a hair over 1 ohm on every plug, which looks pretty normal to me, so I decided to check voltage at the terminals when the glow plugs are cycled. I was surprised to see only 7 volts. Is that normal? It climbs a little as they're left on, and I can clearly see the indicator coil in the dash glowing too, but this is a 12 volt tractor, so I don't understand why I'm seeing voltage that low. I'm just trying to figure out if I have a wiring issue or if this is normal voltage to be seeing.

By the way, the battery has plenty of juice and the engine is turning plenty fast. It'll crank and crank if I ask it to.

grsthegreat · Jan 25, 2022

You need to get the battery load tested. I just replaced the battery on my DK45 for almost the same problrm. Tracyor turned over, but glow plugs not getting juice. I load tested the 900 cca battery, it tested at 380.

i replaced battery and its back to its old self. Fires up great.

Robin Veerman · Jan 25, 2022

How fresh is the fuel? Do you know what the cetane rating is? Ask the attendant….if they even know what you’re talking about. Switch to another depot and preferably one with good turnover. Or add a quality cetane improver. I’ll bet that you’ll notice an improvement, barring any other issues. It does sound like you’re breaking it in though. Give it a good workout if you can.

RandR10 · Jan 25, 2022

grsthegreat said:
You need to get the battery load tested. I just replaced the battery on my DK45 for almost the same problrm. Tracyor turned over, but glow plugs not getting juice. I load tested the 900 cca battery, it tested at 380.

i replaced battery and its back to its old self. Fires up great.

Thanks I'll look into that.

RandR10 · Jan 25, 2022

Robin Veerman said:
How fresh is the fuel? Do you know what the cetane rating is? Ask the attendant….if they even know what you’re talking about. Switch to another depot and preferably one with good turnover. Or add a quality cetane improver. I’ll bet that you’ll notice an improvement, barring any other issues.

Fuel is just a couple weeks old. I ran almost all the old fuel through it before refilling with fresh stuff. Didn't seem to make any difference when the new fuel went in. Not sure what the cetane rating of it is.

RandR10 · Jan 25, 2022

I don't have access to a load tester right now. Pretty sure I'm on the tail end of covid and don't want to spread it around, so I'm stuck home for the next few days until I'm completely over it. Anyway, I did check voltage across the terminals and I've got 12.5 volts, and that's after cycling the glow plugs a few times. Also, like I said, it cranks really well, and doesn't slow down at all if it doesn't start right away. Pretty sure the battery is tip top. The question remains, is that 7 volts I'm reading at the glow plugs normal?

grsthegreat · Jan 25, 2022

Place the voltage tester on the battery and watch the valuse on the battery voltage when cycling glow plugs. If battery voltage also drops into the 7s, that would explain whats happening.

RandR10 · Jan 26, 2022

grsthegreat said:
Place the voltage tester on the battery and watch the valuse on the battery voltage when cycling glow plugs. If battery voltage also drops into the 7s, that would explain whats happening.

Voltage at the battery terminals drops to 11.8V when I hit the glow plug switch.

RandR10 · Jan 26, 2022

So I've done some more research and just expanded my search to Kubota stuff since this tractor is so close to the L245. Looks like 6-7 volts is normal for these systems? I'm thinking I'll look at fuel system next. I might have a leak in the hard lines and I'm getting air ingress.