I have a 2014 (i think, cant remember for sure and its already dark here) L3901 HST with 504hrs. Tractor has always been great until a month ago. It was feeling down on power so I changed the fuel filter and cleaned out the water separator real well. After that it was back running like normal. Now today I start it up and it was just idling warming up. After about 45 seconds of running it started knocking and blowing white smoke heavy. I shut it down and checked the water separator, it was full and clean still. Had to leave for a bit. When I got back I tried starting it again. It was slow to start but once it fired up it was running smooth at idle. Same thing after about 45 seconds it started blowing white smoke and knocking again. I'm at a loss of where to start with this thing. If funds were better I would just load it up and take it to the dealer but that is not an option right now. Any help would be greatly appreciated!
L3901 White Smoke and Fuel Knock
- Thread starter JJones
- Start date
jyoutz
Well-known member
Equipment
MX6000 HST open station, FEL, 6’ cutter, forks, 8’ rear blade, 7’ cultivator
whitetiger
Moderator
Staff member
Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Check the fluid level in your radiator, not look at the surge tank but remove the radiator cap and look at the level.
Runs With Scissors
Well-known member
Equipment
L2501 TLB , Grappel, Brush Hog, Box Blade, Ballast box, Forks, Tiller, PH digger
Did you happen to notice a "sweet" smell to the white smoke?
I know on gas motors a sweet smelling, thick, white smoke is an indicator of coolant being burned.
I know on gas motors a sweet smelling, thick, white smoke is an indicator of coolant being burned.
No this was at cold start. And no regen lights at all
I will look and see where its at.
No it smelled like raw fuel
After further looking at it I think the supply fuel pump has gone bad. Its pumping but not near what it needs to. Thats why it will start then starts falling off. I was listening to it and its no where near the sound it used to be. Have one on order now. The only review on it was positive and for another guy that replaced his for a L3901 lol. Should be here on the 1st
it'd be pretty easy and pretty quick to properly diagnose if you had diagmaster. But you're not a dealer, and won't have full access, so it's considered "dealer only" (unfortunately or fortunately--depending on how you look at things).
I assume you mean "lift pump" because you can't check flow from the supply pump without special equipment...supply pump is the high pressure pump mounted to the engine. Pressure from that pump can get up around 28,000 psi depending on what the ECU wants it to have...along with the scv control.
don't forget to check the fuel flow from the tank before replacing the lift pump. I did this years ago before I had full access to diagmaster, replaced a lift pump because wasn't much coming out of it. Wasn't much coming out after replacing it either, found out that the tank outlet was plugged with algae. Fixed that and it worked fine.
I assume you mean "lift pump" because you can't check flow from the supply pump without special equipment...supply pump is the high pressure pump mounted to the engine. Pressure from that pump can get up around 28,000 psi depending on what the ECU wants it to have...along with the scv control.
don't forget to check the fuel flow from the tank before replacing the lift pump. I did this years ago before I had full access to diagmaster, replaced a lift pump because wasn't much coming out of it. Wasn't much coming out after replacing it either, found out that the tank outlet was plugged with algae. Fixed that and it worked fine.