ZD331 stalling problems

[Hay Dude]

I cut a huge steep hill with my ZD331. Ive done it 20 times this year with no issues.
Cut it Monday and it would begin bucking and stalling at the bottom of of the hill and then after about 10-20 seconds it would recover. Whitish smoke and rough running.
At first I thought the tanks must be low enough on fuel that its sucking up air, but with both at 1/3-1/2 full and having done this hill many times before, that didnt make sense. Did it with both tanks.
Going up hill or flat, it ran fine. Keep in mind this is a 9 hour day of cutting, so there was plenty of time on flat ground for it to stall, but it didnt happen, or at least I didnt notice it. But it nearly stalled at bottom of hill every time.
I wouldnt have been surprised if it was fuel filters, but they would cause low power, stalling nearly everywhere.
Was beginning to think water or debris in tank??? Anyone have similar problems?

 

[artfull dodger]

I would pull both fuel pickups on the tanks, inspect the screen on the end of the tube and make sure its laying in the bottom of each tank when you reinstall. I have seen about everything from the pickup tubes falling off, leaf and a dead bee stuck to the screens or one that the pickup would curl back up after it hit the bottom of the tank so the pickup wasnt pulling near the bottom. Yes, fuel filters plugging up will be low power/sudden power loss all the time. Could be some algie in the tank that the side hill work sloshed into the pickups, then on flat ground it sloshed away from the pickup tubes. Algie can form in diesel fuel tanks, some biocide in both tanks might be in order as well along with some power services fuel additive. Mike

 

[RjCorazza]

A bad lift pump can cause what you describe. My 326 got the fuel pump wires ripped off several years ago and the engine would run most of the time, but would stall out on hills.
I chased fuel problems on my 331 for a while and ended up adding a 2 micron filter and secondary lift pump. It's been fine for the past 1200 hours or so.
Good luck, and report back !

 

[Hay Dude]

I have been meaning to update you on the cause of the stalling.
Dirty tanks.
I had both tanks removed, washed clean, dried, new fuel filters and reassembled.
Runs fine, stalling a thing of the past.
Only downside is now my low fuel light on the reserve tank quit.