Oil & Fuel JD 770 tractor running out of fuel with a full tank, why?

[WmRCraig]

MY JOHN DEERE 1997 770 DIESEL TRACTOR RUNs GOOD FOR AN HOUR THEN ACTS LIKE IT IS RUNNING OUT OF FUEL, I HAVE REPLACED THE FUEL FILTER, DRAINED THE TANK, PUT IN NEW FUEL, CLEARED THE LINES FROM TANK TO FILTER SYSTEM. IT RAN GOOD FOR ABOUT ANOTHER HOUR THE STARTED TO SLOW DOWN AGAIN, FINALLY GOING DEAD. IF I LET IT SET FOR A LITTLE WHILE IT WILL CRANK AND RUN FINE FOR ANOTHER HOUR... I NEVER HAD THE PROBLEM IN COOLER WHEATHER JUST SINCE IT HAS GOT UP INTO THE 90'S. THIS TRACTOR ONLY HAS 760 HOURS ON IT AND HAS BEEN WELL MAINATAINED. HAS ANYONE ELSE HAD THIS PROBLEM?

 

[WmRCraig]

help wanted..

 

[MMagis]

I can only suggest what I have run into. Pull the petcock and look for bugs/debris. I've had to do it more than once.

 

[zzvyb6]

Aren't there 2 filters on that rig? Mine has one below the tank and one up at the motor on the right rear side.

 

[RoyJackson]

Almost sounds like vapor lock, but I've never heard of a diesel (or fuel inject gas) engine having that problem.
Is that 770 running hot? They normally run about 1/4 into the green.

 

[Egon]

Check the fuel tank vent or the tank for debris inside.

 

[irwin]

Check the fuel tank vent or the tank for debris inside.

It certainly sounds like a vent issue. I'd try loosening the fuel cap when it starts acting up just for the heck of it. It's easy enough to try.

Now, I haven't heard of the 770 losing vent and creating a vacuum in the tank, but it has happened on other machines. If it's not debris in the lines or vacuum in the tank, or a cooling system problem, check the fuel shut off solenoid... it might be slowly closing ie: going bad.

BTW, I had a 770 for a few years, great little tractor..

 

[kennyd]

It certainly sounds like a vent issue. I'd try loosening the fuel cap when it starts acting up just for the heck of it. It's easy enough to try.

Now, I haven't heard of the 770 losing vent and creating a vacuum in the tank, but it has happened on other machines. If it's not debris in the lines or vacuum in the tank, or a cooling system problem, check the fuel shut off solenoid... it might be slowly closing ie: going bad.

BTW, I had a 770 for a few years, great little tractor..

Good advice, open the fuel cap when it starts to die-if you hear a big whoosh sound and the engine runs fine then you need a new cap.

 

[Kevin M]

I had a similar problem with my 755 it turned out to be the electric fuel pump (I'm not sure if your tractor has one ? ) Anyway the reason that pump died ( I think ) was because the tank and brass screen in the tank, was packed with black/ green Algae that seems to thrive in Diesel fuel. I installed the new pump and cleaned the screen and tank , the tractor runs better then new !

 

[RoyJackson]

...was packed with black/ green Algae that seems to thrive in Diesel fuel. I installed the new pump and cleaned the screen and tank , the tractor runs better then new !

I wonder how Mr. Craig made out with his 770?

If your tractor sets for an extended period of time, it's worth putting a stabilizer or other additive in the tank. Some of these additives have an anti-bacteriological agent to prevent that algae build up.