Yes, it is an eec system. I believe built by Bosch. The large m tractors eec systems are Nipondenso
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Kubota 3901cranks but wont start
- Thread starter Poophead
- Start date
No matter what ultimate fuel system a tractor has it isn't going to run unless it is getting fuel! checking the fuel delivery from the tank through the primary filter, lift pump and main filter as JerryMT says is still a good place to start!. If you ARE getting fuel through the bleeder on the main filter with the key on it is time for Diagmaster. There is just no other way of knowing where or whether those electrons are flowing.
I agree. If the rail is being pressurized and adequate fuel is available at the high pressure pump, the problem is in the electronic components. Check all the connectors for clean contacts and good connections. These are the weak points in EEC systems. I don't know how timing is sensed but if there is a crankshaft position sensor(CPS)as on our Ford Powerstroke common rail system, these can be problematic leading to no starts and rundowns.
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Poophead, does the dash go through its self-test and the glow-plug light stay on a little while before it goes out?
If hourmeter shows hours only, and no codes, chances are there is another issue elsewhere. I say this because the ECU monitors everything on the engine. If there is fuel starvation to the point that it won't run, it'll throw a code for rail pressure below threshold, or rail pressure sensor failure code. I forget the actual P code numbers, but that's the nuts and bolts of it.
Diagmaster will find the issue quickly, used by a tech who knows what to look for. IF it's still got any warranty on it, quit dinking around with it & have a tech hook diagmaster to it. That's the ONLY way to do diagnosis on these new tractors, exactly like a diesel pickup truck or most newer 18 wheelers. The other option, throw some expensive parts on it and eventually you'll find/fix the issue. And a lot of the parts on these things are nowhere near cheap. Once one figures in the cost of the major parts, $100 for a tech's time is dirt cheap.
Diagmaster will find the issue quickly, used by a tech who knows what to look for. IF it's still got any warranty on it, quit dinking around with it & have a tech hook diagmaster to it. That's the ONLY way to do diagnosis on these new tractors, exactly like a diesel pickup truck or most newer 18 wheelers. The other option, throw some expensive parts on it and eventually you'll find/fix the issue. And a lot of the parts on these things are nowhere near cheap. Once one figures in the cost of the major parts, $100 for a tech's time is dirt cheap.
lugbolt, I was trying to determine if the CAN bus was working to the dash computer, that would give us an idea if the ECU was at least working. If the glow plug light stays on after the dash does its self test, that would tell us that the ECU is talking to the dash computer, which is done over the CAN bus.
I did have to replace a ECU on a L4060 just last fall so they DO sometimes fail! I don't remember the exact code but it did show a code. The grand L tractors show more information on the dash than the basic L's do
Kubota service said it was the fuel pump. I dont see how because when ya turn the key on , fuel filled the water seperator quickly, and when i bled the fuel filter, fuel shot out of there too. I just hope it works after they put the pump on .
Well there are THREE fuel pumps! The electric pump, the fuel pump and the supply pump! Let us know which one if you can. ( supply pump is $3400 in Canada so you won't want to replace it very often!)
Three fuel pumps? I only found 2 on mine.
Starting with the tank: The fuel flows via gravity to the water separator, then it goes into the 12V lift pump, where it leaves under pressure and goes into this octopus looking device that God only knows where all those hoses take fuel (probably the Tier IV DPF communist plot can that obscures access to the injectors) then on through the spin on fuel filter and on to the gear driven injection pump.
What/Where is this 3rd pump?..... For clarity:
Lift pump (12V runs with key on, helpful in priming fuel filters)
Injector Pump (driven by engine - sends fuel under very high pressure to injectors)
Starting with the tank: The fuel flows via gravity to the water separator, then it goes into the 12V lift pump, where it leaves under pressure and goes into this octopus looking device that God only knows where all those hoses take fuel (probably the Tier IV DPF communist plot can that obscures access to the injectors) then on through the spin on fuel filter and on to the gear driven injection pump.
What/Where is this 3rd pump?..... For clarity:
Lift pump (12V runs with key on, helpful in priming fuel filters)
Injector Pump (driven by engine - sends fuel under very high pressure to injectors)
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Yes it is quite the little rat's nest of tubes in there. I have been meaning to start a thread on this with pictures, but it takes fiddling with computer first to get pics from phone resized. Anyway to get you started, fuel is sucked from the tank through the water separator by the electromagnetic pump, using Kubotas names for them. On mine it goes through a check valve next, on 01s it looks like check valve is later. The middle of the octopus is a reserve tank aka sub tank that actually serves to mix new and overflow fuel from the rail. It then is sucked out of there and through the fuel cooler by the radiator by the feed pump. The feed pump pushes it through the fuel filter to the supply pump, which is the high pressure pump for the rail. The reserve tank octopus has 2 inputs and 2 output lines. 1 output is line to cooler but one goes back to fuel tank. The feed pump is below the fuel filter and is pretty visible. The electromagnetic pump can be found by following the line from the water separator, has wires hanging off it. The supply pump is attached to the block, not very easy to see.
Addendum, most visible when you look at the tractor is a T in the tubes, one of which is a line off the fuel filter. It joins the overflow line from reserve tank that is going to fuel tank. I am not sure how and when it flows, but maybe it is to make sure unfiltered fuel when you are bleeding the filter after changing it, doesnt get up to supply pump?
coachgeo
Well-known member
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L225 w/woods Few Mowers & Back Blade, D722 in Motorcycle (Triumph Tiger), LMTV
This may be an air bleed out of the fuel filter. It is there for under operation air bleeding. Can handle small leaks inherent to a shaky diesel. This configuration is same as my old Mercedes diesels. Common for this line to Tee up into the return line. It returns excessive air that rose to top in fuel filter to the tank. Also there should be a check valve and is probably at/inside the filter housing. Air can open the check valve and bleed out, but fuel from return line can not get back into the fuel filter .... it's flow to the tank is needed to move the air along.
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OK so using Kubota's terminology:
Electromagnetic Pump = 12V Lift Pump
Feed Pump = ??
Supply Pump = Engine Driven Injector pump
How is the feed pump powered? Is it a gear driven pump also? How would you diagnose a bad feed pump? One would think that with the lift pump pushing and the injector pump sucking there would be no need for yet another pump?
Electromagnetic Pump = 12V Lift Pump
Feed Pump = ??
Supply Pump = Engine Driven Injector pump
How is the feed pump powered? Is it a gear driven pump also? How would you diagnose a bad feed pump? One would think that with the lift pump pushing and the injector pump sucking there would be no need for yet another pump?
Follow the fuel hoses. The fuel goes from the electric pump, to the distributor, to the fuel cooler, to the feed pump, to the main fuel filter, to the supply pump, to the common rail, to the injectors. the injectors are supplied with constant high pressure fuel and inject when the ECU gives them a signal via the electrical connection on the top. the ECU determines the correct timing and amount to inject from inputs it gets from the crank sensor, the cam sensor, the throttle position sensor, the ambient air temp sensor, the coolant sensor, the mass air flow sensor and maybe a few more that I've forgotten about. Any one of those things will cause problems and may cause it not to start.
Eserv, I am very familiar with common rail injection. Your description of the process is quite clear and expertly done. What powers the feed pump between the fuel cooler and the injector/supply pump?