B7000 starts, runs for a few seconds then stops

[pistonbroke]

I've changed the fuel filter, cleaned out the lines and cleaned the gunge out of the diaphragm/fuel lift pump.

If I keep trying, eventually it will start and by frantic wiggling of the throttle keep going. Then after 30 seconds or so it runs absolutely fine.

Any ideas?

 

[Motion]

You didn't say if this happens every time you go to start it. Are you running good clean fuel? Did you properly bleed the the injectors after changing the filter, were you getting good fuel when bleeding. Does the tractor have glow plugs and if so are they functioning properly?

 

[pistonbroke]

Thanks for reply. I haven't bled the injectors, but did bleed from the top of the injector pump. Fuel flowing from there freely as I turned over the engine. The engine has run for several hours since then. The fuel should be OK. The tractor has glow plugs and they're working OK. Considering the amount of gunk that had got past the filter into the fuel lift pump I wouldn't be surprised if some made its way to the injector pump/injectors. Are there any more filters/screens between the fuel lift pump and the injectors do you know? I can't see any - but that's what the problem feels like, gets some fuel to start but struggles to get any more in. Eventually when it's warm and things are flowing more freely it's OK. Reluctant to take the injector pump to bits if I don't have to!

 

[pistonbroke]

PS Yes Happens every time I start it from cold. OK re-starting from warm.

 

[Motion]

All of the gunk came from the fuel tank, I'd recommend removing the contents and see what's in the bottom, clean accordingly, also consider installing a prefilter until every thing is cleaned up. Ensure that the pump components are in good condition. Bleed the injectors from the top of the injectors. How did you determine the glow plugs were functioning correctly? Pending how many hours the engine has, a compression test may be in order, pumping fuel into a no start engine can do damage to the rings and cylindr walls. If you feel that dirty fuel got pass the filter and injector pump to the injectors, they may not be spraying properly when was the last time they were cleaned and tested?

 

[pistonbroke]

OK thanks. I'm going to do those things. I've had the tractor for very many years and the injectors have never been out. I'm from the ''if ain't broke don't fix it'' camp - but to be fair it probably deserves some TLC.
Glow plugs checked by ohmmeter. I'll let you (and anyone else interested) know what I find.

 

[Motion]

It's good that the glow plugs were within tolerence, are you certain that you're applying a full 12 volts when called upon?

 

[GreensvilleJay]

Step #1, remove fuel tank, drain and CLEAN really ,really good.
Sounds like your tank was the source of the problem,so you have to take of of that now. I'm thinking maybe 'black algae' or something else ?

Step #2, be sure step #1 is done !

Step #3, new filters and 100% fresh fuel (do NOT use old !), prime as needed......see what happens.

You might get lucky and not have to clean the injectors...others will know how it need be.

 

[torch]

It starts right up, then dies. It runs fine if you can keep it running for 30 seconds or so. It's just between that initial start and the 30 second mark that you have problems? Have I got that right? Is this every single time or just first start of the day or?

Any sign of seepage around the lines between the pump and the injectors? Maybe air is getting in that line when it sits. Another possibility might be the governor is sticking. It has a starter spring that applies extra fuel when it's cranking until it starts. Perhaps some of the previous spooge got in that mechanism.

 

[North Idaho Wolfman]

Sounds like it could be an issue with the start spring on the governor, or an issue with the injection pump.

 

[pistonbroke]

Thank you all for your replies. Never known anything like it. Took tank off, cleaned it out, pressure washed it, dried it. New fuel filter. Lift pump off and cleaned. Injectors out, disassembled, cleaned, spray pattern checked. 12V at glow plugs and both working fine. Fresh diesel. Still same problem!
Runs perfectly once it's going. The problem is just as you describe torch, feels like it's going to start immediately, dies. After 7/8 attempts with the same thing happening it eventually goes.

I can't see any seepage on the fuel lines to let air in - but I think I'll replace them anyway.

Can someone tell me how to check the start spring on the governor please?

I'm going to do these other things before I resort to fiddling with the injector pump.

 

[pistonbroke]

For anyone having the same problem and visiting this thread - it's now sorted and tractor is back to starting and running well. Having cleaned out the tank, fuel lines, changed filter, lift pump and injectors I was foxed as to why I had the same problem with fresh fuel. Turned out to be that I store my diesel in a 500 litre IBC. I noticed when I lifted out my submersible pump having refilled the tractor tank - it had a yukky greasy slime on the pump's stainless steel body. To cut a long story short this turned out to be 'diesel bug' and no matter how many times I put 'fresh' diesel in my tractor, this sticky stuff was tending to hold closed the very lightly sprung popett valve on the fuel pump, (it manages to pass the filter)hence it would start on the fuel in the lines - then stop almost immediately.
I've now added biocide to the diesel in the IBC and the tractor tank and run it for an hour or so and it's fine - and has continued to be for the last 2 weeks.
Thanks for the suggestions from contributors above.

 

[Henro]

For anyone having the same problem and visiting this thread - it's now sorted and tractor is back to starting and running well. Having cleaned out the tank, fuel lines, changed filter, lift pump and injectors I was foxed as to why I had the same problem with fresh fuel. Turned out to be that I store my diesel in a 500 litre IBC. I noticed when I lifted out my submersible pump having refilled the tractor tank - it had a yukky greasy slime on the pump's stainless steel body. To cut a long story short this turned out to be 'diesel bug' and no matter how many times I put 'fresh' diesel in my tractor, this sticky stuff was tending to hold closed the very lightly sprung popett valve on the fuel pump, (it manages to pass the filter)hence it would start on the fuel in the lines - then stop almost immediately.
I've now added biocide to the diesel in the IBC and the tractor tank and run it for an hour or so and it's fine - and has continued to be for the last 2 weeks.
Thanks for the suggestions from contributors above.

Great that you took the time to report back!