John Deere Yanmar diesel engine just stopped

[Nigelr]

Thanks so much Pump Guy, I'll try that in the morning

 

[Nigelr]

Thanks again Spanner, i'll check that. I did renew the fuel filter so not impossible it's got a non-return valve that's got stuck, or something.

 

[Nigelr]

Okay I did that. Fuel flows well out of the pipe I pulled off right at the pump, from the electric pump, and the piston in the overflow was free and came out easily with a weak little magnet. I cleaned it and the cylinder up anyway, bled it as you guys suggested, and bled it again at an injector, but sadly it hasn't made the difference.

Just to recap, it was running perfectly as usual then after about 40 minutes' running it cut suddenly and totally and hasn't even hinted at firing since. It coincided with a jerk as I went from reverse to forwards, I have no idea if that's a factor. Its's 3/4 full of fuel.

So I'm bracing myself for taking the fuel pump off?

 

[Spanner]

Do you have any white smoke coming from exhaust when you crank the engine?

Do you have compression when the engine cranks?

The white smoke is compressed, but not burnt, diesel. Good news of a sort.

I'm wondering all sorts of scenarios - none of them good news...

:wrench:

 

[Nigelr]

There's normal compression, no white smoke from the exhaust.

 

[Egon]

When you turn the key do you get the solenoid click. When cranking does any fuel come out of the discharge of the injection pump?

 

[Coyote machine]

To the OP, can you further describe the 'jerk' you mentioned that occurred when you went from reverse to forward? What were the exact conditions, going up or down a hill, full stop before changing directions, etc.
Everything fuel related has checked out so far, and it's cranking, but for some reason it won't fire fuel and start. I wonder, out loud, if somehow it's 'confused' as to whether it's in neutral when it is cranking, but it's thinking it's in gear and thus won't allow fuel flow? Something like a faulty sensor/wires touching that are creating a 'fake news' signal in the brain?

 

[Nigelr]

I'll have to check about the solenoid click in the morning to be absolutely clear. There are some clicks but some are from the electric fuel pump of course. Some fuel came out with the plug loose but as to how much I'll get my wife to crank and look more closely and take a bit of video.

Also I need to update my post about smoke, checking again there is some vapour though I'd call it grey. I'll get some video to post of that too.

Anyway I've towed it under cover and got the battery on charge.

Thanks!

 

[Nigelr]

Thanks for your thoughts Coyote machine. Being hydrostatic I can shift from forwards to reverse quickly with the pedals being next to each other. I was manoeuvring at the end of a run, lining up to go back, so low speed but not waiting for it to come to a stop.

As far as I know it's in neutral by default when the travel pedals are fully up, I press the brake pedal to get it to crank, with the cylinders lever in stop too.

With the way it stopped so suddenly, no cough or splutter just died, I wouldn't be surprised if it was some kind of sensor.

 

[thepumpguysc]

Just remove the inj. pump shut-off solenoid.. located on the back of the inj. pump..
IF there are any sensors telling it to shut off, you'll bypass them.. JUST DONT BE IN THE WAY IF IT STARTS..
Your going to have to bleed the air out of the system.. Loosen the lines AT THE INJECTORS..
KINDA DANGEROUS if the solenoid is out.. USE CAUTION..

 

[Coyote machine]

Thanks for your thoughts Coyote machine. <snip> No Problem, trying to help... What do you mean by the following? >>>I press the brake pedal to get it to crank, with the cylinders lever in stop too.

With the way it stopped so suddenly, no cough or splutter just died, I wouldn't be surprised if it was some kind of sensor.

That's where I'm headed; possibly some conflicting sensor reading telling it to crank but not start, (hence no fuel delivery)...

 

[Spanner]

There's normal compression, no white smoke from the exhaust.

No white smoke means no fuel passing through the injection pump. This co.incides with your earlier report of minor sputters when loosening an injector pipe (I think).
So you have narrowed the problem to the injection pump and there are some more choices now...

I think we confirmed the solenoid operates correctly?
The pump needs to rotate internally to work so we need to confirm the gear drive is in operating order. Are you interested in further disassembly?

Someone asked about the brake...
This is a Golf Course mower. The brake pedal depressed allows the interlock circuit to let the starter motor crank the engine. The operator can depress the pedal himself or he can set the Parking Brake. Either way the switch is activated and the engine will crank IF the blade engagement control lever is set to off. In fact it is known as the Mow/Transport lever. Set to "Transport" it too, has an interlock switch input to the Heartbeat box.
:wrench:

 

[Nigelr]

Yes Spanner I think we have arrived at the point where some disassembly is the next step, any guidance would be a great help!

 

[Nigelr]

Just remove the inj. pump shut-off solenoid.. located on the back of the inj. pump..
IF there are any sensors telling it to shut off, you'll bypass them.. JUST DONT BE IN THE WAY IF IT STARTS..
Your going to have to bleed the air out of the system.. Loosen the lines AT THE INJECTORS..
KINDA DANGEROUS if the solenoid is out.. USE CAUTION..

I did try this Pumpguy, I forgot to mention, sadly it didn't fire.

 

[Nigelr]

That's where I'm headed; possibly some conflicting sensor reading telling it to crank but not start, (hence no fuel delivery)...

yes the mow/transport lever as Spanner says. The symptoms would fit with a sensor, but there doesn't seem to be one. We have all the electrical side working so now it's something mechanical by the look of it.

 

[thepumpguysc]

If your intent on pulling the inj. pump.. get a book.. the timing on those things are critical..
Its actually set w/ a dial indicator, but can be done w/o it.. just mark everything.. pump hsg to block..& especially the front timing gears..
There are a couple of pumps on ebay cheap.. but used..
I'd be reluctant to buy them unless I needed a core or some expensive parts.. OR they had a good return policy..
The main pumping unit on that pump is around 1000.00 alone.. & NOT a DIY project..
Sorry for your troubles.. TPG

 

[Spanner]

The 3235C doesn't have "Sensors" in the modern sense of the word. It has "Interlock Switches"

We now know the 'switches' are allowing the Solenoid to "Pull" and the Starter to "Crank" plus there is fuel up to the Injection Pump.
But no "Bang"...

Do you have the 'Technical Service Manual' Nige?

 

[Egon]

If the fuel solenoid does not click the fuel pump may not engage.
I'm not sure but think the solenoid engages/disengages the cam followers on the injection pump. It does not shut off the fuel supply.

If you do want to look at the pump there might be a plate on the side that can be removed and allow you to see if it is working.

Try not to get involved with the timming or the governor.

 

[Nigelr]

thanks Egon, Spanner, Pumpguy, looks like I need the full manual as you're saying, that's my next step.

 

[thepumpguysc]

No plate on the side.. its a closed system.. I HATE'M ..
The worst designed injection system EVER produced.. I feel bad for anyone that owns one.