B2620 engine "stuttering" occasionally, sometimes stalling

[KillerBeagle]

Just a few days ago, my 600-hour B2620 started this odd stuttering behavior when the weather got slightly colder (just below freezing). It warms up and idles just fine, but under load, while moving, the engine tries to stop every few minutes. Usually it recovers and starts running again; about once in 5 times it stalls out, but I can immediately start it with the key. I can "recreate" the same behavior just by turning the key off for a half-second and then back on. The work I'm doing - dragging an arena and spreading manure - is all on pretty bumpy ground, so it seems like the shaking could be causing problems.

I'm trying to figure out the most likely places to start looking. I feel like it's electrical, like it might be a loose connection or a safety switch that's making intermittent contact. Are there any common failure points on the B series that would cause this?

Any other places to look, such as bad fuel, clogged fuel filter, etc?

It's supposed to start snowing in a few days, and I usually volunteer to help plow the roads in our neighborhood. The last thing I want is to leave a dead tractor stuck in the middle of the road...

 

[number two]

Can you bring it inside?
Others will be along shortly.
Good Luck!

 

[rScotty]

Are you sure your fuel has winter de-icer? Adding some extra won't hurt.
Those symptoms sound like what happens when a fuel filter begins to clog up with wax and gel because the fuel is not winterized.
That's just a guess, but it happened to me last year.

 

[RjCorazza]

In addition to the potential fuel problem, a cold and stiff seat can cause the operator presence safety switch to not activate. If it's going in and out rapidly those symptoms would be the result... It happened once on my diesel zero turn.

 

[Carl_NH]

Check your fuel and air filter - mine started stuttering twice - once the fuel filter was nearly collapsed, - replaced it and it was fine. The second time doing a lot of dirt work in dry and dusty conditions - became harder to start - air filter was very dirty - replaced and it's been fine since.

Now I replace fuel and air filter about every 150 hours and check them regularly.

It could be electrical, but usually it's on or off not intermittent, or stuttering,

 

[dodge man]

When’s the last time you changed the fuel filter? If it’s been a while I’d put a new one in. It seems like temps have to get down closer to zero before fuel gels but it might be a good idea to add an anti gel additive.

 

[KillerBeagle]

Thank you all for your suggestions! I went ahead and replaced the fuel filter, and will report back whether that cured the symptoms.

Believe it or not, I checked my email and I had ordered two fuel filters in December 2019, but apparently forgot to use them. That means I've gone through several oil/hydraulic/air filter change cycles without changing the fuel filter. D'oh!

 

[KillerBeagle]

Well, I changed the fuel filter (it didn't look obviously dirty), and the first time afterwards it ran fine, though I didn't put much a load on it. Next time, after some colder weather with temps down to 18F during the night, it was even worse than before changing the filter. It still runs fine at idle, but there were a few times when, each time I pressed the pedal to go forward, it would start to die. If I kept pressing the pedal, it would stall; if I let up, it would recover.

I'm thinking now the most likely culprit is fuel related, maybe icing. In western Washington they don't change the diesel grade like they did in Idaho. Anyway, I'm going to find some anti-gel anti-icing additive and see if that helps.

 

[JOE G]

My BX would do this and the fuel line was clogged at the tank size, I removed rear filter and didn't have much flow, blew into it and it came rushing out. I cleaned tank and all is good.

 

[number two]

Seat/Safety switch seems more likely to me.
Good Luck!