2025R Mystery

[jdwebster]

What are the hydrostatic transmission checks? Could it be causing a drag on the engine by having an internal problem?

Fuel, air, compression.

Per your report, compression seems good.

Has the entire air intake path been checked, from the first opening to outside air through the filter and to the engine intake? No chance there is a nest in there somewhere or a tube collapsing that could be starving the engine during peak demand? Any blockages in the *exhaust*? Muffler baffles broken and obstructing flow, nest in the canister, soot buildup? Exhaust flow is just as important as intake.

Similar for the fueling - any restriction causing starvation at peak demand? They replaced the injectors - why? What made them suspect fuel delivery? Did you tell them about the biodiesel (which still seems to be the origin of your problems), what could that affect in the fueling system?

It's good they verified on the dyno there is a problem. That eliminates any of the ideas about fuel pickup issues up-hill or pinching lines at weird angles or anything happening on the PTO- it's a purely engine-related problem. Fuel, air, compression.

The tractor is stored in it’s own shed, so pretty safe from vermin. I’ve taken the air filter out and replaced it and everything looks pretty darn clean and new, and I’m sure this has been checked by multiple mechanics. IDK about the exhaust. They replaced the injectors because for the same reason they’ve done everything else- because JD told them to do it. Because the tractor is under warranty, Cal Coast has to communicate with JD and do what they say in order to get paid for it. It’s a crappy dynamic and one reason it feels like JD is a law firm that happens to make tractors- very slow, risk averse and bureaucratic. They know about the biodiesel but, again, once I replaced the fuel, the tractor ran fine for a while thereafter. All other tests of the fuel system have apparently checked out. The last mechanic who came said exactly what you said- fuel, air, compression. And yet….???

 

[Fuddyduddy1952]

Maybe sell & get a 2038r. It's 4" wider from what I see. Yours should bring top dollar 2 yo & 75 hours.

 

[beenthere]

Hard to sell something that isn't working right and you know it.

 

[Fuddyduddy1952]

Not if trading it in to the selling dealer.

 

[rScotty]

Mechanic came and replaced the injectors. No change. =( If anything, it’s getting worse. Can’t go 15 feet uphill on a 20% slope with the sprayer and fan on without trying to stall.

In the original message the injectors had just been replaced. Why replace them again?
The only diagnostic info you know so far for sure is the dyno confirms that the problem has to do with full power operation. I think you need another piece to the puzzle. Here's a couple of simple tests - would take a couple of hours and cost less than $100.

One thing that could cause that would be the same thing that caused it originally - the water in the fuel problem when going uphill. I wouldn't discount that until I had taken the fuel tank out and scrubbed it.....probably the filter housing too.
Or do a simple test instead. Just mount a temporary fuel tank on the ROPS and run a rubber line directly to the intake of the fuel pump. Mechanics everywhere use that trick when a fuel tank is suspect or removed. In fact, you can buy that whole setup on Amazon for about $25.00. It looks like a hot water bottle and a hose. In fact, the mechanics at the dealership probably already a remote tank like that available in their shop. They could hook that up and run the dyno again. Or you could do it yourself and try it in your vineyard.

The other thing that could cause the stalling problem is that for some reason full throttle at full load operation is causing the engine or tranny to overheat. I'd start by replacing the existing temperature light or simple temp gauge with a real temperature gauge that reads in degrees. Then see if the stalling is accompanied by a sudden rise in engine temperature.

If neither of those tests show you something, check the temperature of the HST transmission. Since there isprobably no place for a gauge on the HST, just strap a temperature sensor to the HST return hose.

With those tests, at least you would have info.
Or you could just continue to watch kids with no idea about mechanical things continue to replace parts on their dime & time....There's some interest in doing it that way as well.

You know, the 1025r is really not an ag tractor. Several manufacturers do make narrow ag quality vineyard tractors...but I'm guessing you already know about that.
Luck,
rScotty

 

[jeepcoma]

rScotty's advice is spot on - try to eliminate as much of the fuel system as possible. We know you had a fuel issue, both with biodiesel of unknown strength (but almost certainly above B5) and also a water-in-fuel issue.

At one point, you replaced the fuel and filters and it made a positive improvement, for a brief period of time. This suggests there was in fact an obstruction, replacing the filter cleared it up, but the obstruction returned.

Biodiesel blends will attack the hose lines and degrade them, delamination could clog things, it can weaken the hose and perhaps it's not flowing as much as it needs. Anything upstream of the filters would have hopefully been caught, but any lines past the filter wouldn't. Any internal degradation can get worse over time, which is what you have now.

Algae is the other one. If it's growing in a fuel line, or the petcock, or any small passage you can't see and isn't the fuel filters, it doesn't take much to reduce flow. Adding biocide might have killed most of it, but it leaves the blockage, and any living bits will eventually grow. That could be why the problem is coming back and getting worse.

It's worth trying, we still haven't really ruled out fueling as the cause. The fact that it's getting worse over time though, and now can be repeated on a dyno, should make troubleshooting easier...