6068TF275 NO START

[CCC1971]

I have a 6068 in a 125kvw at my jobsite that is giving me fits; it currently has about 2900 hours and was bought used about a year ago. The vid show the unit; my company bought it not long after it came out.

[ame="http://www.youtube.com/watch?v=zTxQ_8shnEE"]http://www.youtube.com/watch?v=zTxQ_8shnEE[/ame]

This thing will start and run fine for about 2 weeks, then won't start without cracking all 6 injectors. I've replaced all rubber and hard fuel lines from the tank to the injection pump. This started this past winter, and I thought it was rotten rubber in the hard line fittings doing it.

While running I do see fuel seeping from the H2O separator, which will cause about 2 drips a minute so nothing major there (will be replacing next inspection). The only other thing I suspect is the lift pump due to having good pressure at the main fuel filter bleed port regardless of how long it sits without running. Ocassionally, fuel will also seep from the return side of the injectors, but don't feel like pulling the manifold off to gain access (no specialized tools on site; have to do everything with basic hand tools).

I usually only have to bleed twice a month to get her started, but that's 2 times too many IMO. Any opinons or help in this would greatly be appreciated.

 

[beenthere]

:welcome: to TBN.

I gather this is a Deere powered generator?
What more can you tell us about the power plant?

History of filter change, pump, and/or other maintenance?

 

[CCC1971]

Thanks. Yes, it's Deere powered; odd, considering the manual sent with it still lists the IR powerplant. I do have a general JD engine manual, but troubleshooting is not specific enough to narrow this issue down.

This unit had a complete fluid and filter change prior to purchase, less than 100 hours ago. Not sure about when the pump was changed but, with that many hours, pretty sure it's due. The fuel is checked constantly prior to service, and I drain the water at least weekly (unit is not used much, but I run it at least weekly).

Not relating to the issue, but an interesting side note: these units have a bilge in the center of the enclosure that captures and collects all the fluids and garbage that collects inside; apparently it had not been drained since new. When I popped the drain cap a most vile stench of rot and decay rolled out, along with some obscenely dark colored liquid and solid mass. It was still draining over an hour later; I had to take a broom handle and punch through the blockage. DISCUSTING!!!

 

[beenthere]

Then I'd suggest taking the unit to a diesel mechanic to check out the fuel injection pump and the injectors, including the fuel line. The gunk you found may just be an indiction of the 'gunk' that is in the fuel lines and even possibly the fuel tank.

A Deere diesel mechanic would be my first choice, but there are plenty of others working on diesels. Knowing the pressures at various points may help, as well as when fuel shutoff solenoid is or is not working. What pressures are when it fails to start may be the most important clues.

 

[CCC1971]

Then I'd suggest taking the unit to a diesel mechanic to check out the fuel injection pump and the injectors, including the fuel line. The gunk you found may just be an indiction of the 'gunk' that is in the fuel lines and even possibly the fuel tank.

A Deere diesel mechanic would be my first choice, but there are plenty of others working on diesels. Knowing the pressures at various points may help, as well as when fuel shutoff solenoid is or is not working. What pressures are when it fails to start may be the most important clues.

Not an option; I'm in Afghanistan and the only mechanic in my company. Knowing that, I need to simplify the troubleshooting process. The fuel tank was drained prior to shipment, and the bottom of the tank flushed prior to refill. All lines have been changed, and clean fuel flow up to the injectors. When it runs they have great pressure. My issue is why the pressure bleeds off when it does; could be a day or 2 weeks later. I've cracked the bleed port on the side of the H20 sep. (located after the lift pump) and it still has pressure. Somewhere between the injection pump and injectors is getting air into the system.

I can continue to troubleshoot but will be blind without a good manual. When it runs it starts right up, is smoke free and runs like a champ.

 

[powrpacks]

I'm working on same engine, different troubles. I was just reading your problem and figured I'd post my thoughts. I would try installing check valves in fuel supply line at various points in the fuel system to see if that prevents bleed off. Other than that, I would pressurize and bubble check the system with air, at different points on suction sides. This might reveal the culprit. Good luck.

 

[Tx Jim]

CCC1971
I'd suggest too repair fuel leak on supply line at H2O separator,install a fuel line check valve. The return line leaking normally doesn't affect ability to start engine.