L4240 Stalls when the ambient temp is hot.

[kleetus]

as the title says, My L4240 stalls when the ambient temp is over 70ish.
I just had a full service done, including fuel filter, oil, and hydraulics. It was happening prior to this as well.

It stalls when its idling, or under load (PTO or not). But only when its hot.

I ran it for 3 hours in the morning dragging a box scrapper and a harrow with no issues, when it was about 50. now this afternoon its 81 and it dies every 30 secs to 3 mins.

I loosened the fuel cap to see if there was a vacuum issue but had no effect.
It doesnt blow any kind of smoke at all, and it will start right back up every time, also with out smoke.
I dont think is a fuel quality issue, since it runs when its cold, the fuel is new, and 2 other farm vehicles use it, so I know its clean.
I have tried hard to recreate this in the cool but it wont.

its a 2011 or 12 if that makes a difference.

thoughts?

 

[Harry in Ky]

Not that I know the answer (because I don't) but when you say it "stalls." Can you describe what that means to you? The engine suddenly quits like you turned off the key? Or it slowly winds down and dies out more like it's running short of fuel? The first symptom would indicate it's probably electrical. The second would indicate it's something else.

 

[kleetus]

well I was mowing today with my PTO at 550 rpms and the tractor at about 2400 rpms, and it will lose all power, idle for a second then stall even with the gas to the floor

Other days I didnt have the PTO running but I run around 2000-2400 rpms usually.

when I start it up, it goes right back up to 2400 rpms

 

[alexpops]

Clean Air filter? clean screen before the intake? EGR valve? If it isn't fuel/could be air is too hot/not enough. Also, check the shut-off solenoid for heat/frayed wires. My ZT was jury rigged by a previous owner & if I accidentally hit the fuel switch, It'll bog under load but keeps sipping fuel until it dies or I kill the mower & just drive (or turn the switch back)

 

[Harry in Ky]

Well to me that sounds more mechanical than electrical. The tractor is old enough that it shouldn't have much other than a seat switch and the typical operator aggravation module that affect it electrically anyway.

When it does this, can you recall whether or not you hear the fuel shut off solenoid click consistently with the key going off and on? Can you see the fuel filter canister from the seat at all or is that all covered? Just throwing ideas around here, none of which I can think of that would be ambient temperature related.

This shouldn't matter either, but what transmission do you have?

 

[RjCorazza]

It's also possible that the electric lift pump is failing. When it's good and hot out, check for fuel flow after the lift pump.

 

[kleetus]

Well to me that sounds more mechanical than electrical. The tractor is old enough that it shouldn't have much other than a seat switch and the typical operator aggravation module that affect it electrically anyway.

When it does this, can you recall whether or not you hear the fuel shut off solenoid click consistently with the key going off and on? Can you see the fuel filter canister from the seat at all or is that all covered? Just throwing ideas around here, none of which I can think of that would be ambient temperature related.

This shouldn't matter either, but what transmission do you have?

I have the HST, but you bring up a point.. when it stalls it sounds exactly like it does when the seat switch is tripped. I might go run it in PTO mode with the seat up to see if it still stalls. do you know if there is a way to disable that?

 

[kleetus]

Clean Air filter? clean screen before the intake? EGR valve? If it isn't fuel/could be air is too hot/not enough. Also, check the shut-off solenoid for heat/frayed wires. My ZT was jury rigged by a previous owner & if I accidentally hit the fuel switch, It'll bog under load but keeps sipping fuel until it dies or I kill the mower & just drive (or turn the switch back)

Had a new air filter as well when I had it serviced. Going to go check for any loose wire.

 

[dstig1]

Debris in the fuel tank is a possibility. Warm temps perhaps loosen things up enough that it gets free and sucked into the inlet where it chokes fuel. Then it shuts off, fuel draw stops and floaters move back out of the inlet for a while until flow starts again. Wash rinse repeat. Or could be some wax-like goo in the diesel doing it.

I haven't had it happen but have read of several on here that have.

 

[Harry in Ky]

I have the HST, but you bring up a point.. when it stalls it sounds exactly like it does when the seat switch is tripped. I might go run it in PTO mode with the seat up to see if it still stalls. do you know if there is a way to disable that?

There's a way to disable most anything. Particularly so on tractors old enough they don't have computers with over riding control over everything. If your experimenting leads you to conclude the issue is indeed electrical (I'm not convinced of that yet) you can actually bypass all of that with some simple tricks. I've done it before on other tractors with similar systems. It's not hard, not permanent, (unless you want it to be) but once done and you operate the tractor for a few days and the "stall" problem doesn't re occur, you can work on narrowing it down and repairing the cause.