Massey Ferguson 1740M Hydro: LOSS OF POWER when hot!

[JWR]

It was stopped completely w no forward speed, level ground (no HST pedal), full throttle and maybe half RPM range achieved. I brought down then to an idle for maybe 2 minutes, then was able to get some throttle response, not full but enough to engage the mower. Then, with the mower up to 540 PTO range I proceeded forward and for 2 seconds it was normal then dropped RPMs with the mowing and forward speed.

I even put the gear in "N" (no HST), still logy but it finally regained strength, once I engaged mower it was kinda okay and slightly sluggish, but then after going back in gear (engaged moving forward) WITH mowing; just too much for it.

Well !! That is the smoking gun in a large sense -- because that example circumstance eliminates all loads, the tranny, etc. This nails the fact that your problem is the engine or it's controls. Sounds awfully simple, even like an oversimplification, but that is a big piece of information. It could have been so many other things. But that does mean the fuel supply is still in the running for causes -- some moving eventual partial flow plug as described in other posts recently...just hard to see how any fuel issue "waits 40 minutes" or how it "happens sooner if under greater load." Hmmm, maybe not so far fetched, since with higher loads fuel is being supplied at a faster rate (and might lead to a 20 minute start of disease rather than 40 minute...?) Your dealer or anyone working on it could rig an "IV bag" of fuel and bypass the tank, the lines the filters and cross them off the possible cause list.

Certainly unscrew the fuel filler cap first (the next time it happens) and see if the issue goes away !! That is so easy it is ridiculous and 81 posts later several of us will be outside trying to slap ourselves up side the head harder if that turns out to be the problem ! Embarrassed to say it fits -- a partial vacuum being created in the tank by fuel usage... 1) it would recover after a while with air leaking back into the top of the tank 2) it would take longer to happen under light loads with less fuel flow and 3) sooner to happen with heavier loads and more fuel flow, etc... geeze!

 

[TopSpeed1]

Well !! That is the smoking gun in a large sense -- because that example circumstance eliminates all loads, the tranny, etc. This nails the fact that your problem is the engine or it's controls. Sounds awfully simple, even like an oversimplification, but that is a big piece of information. It could have been so many other things. But that does mean the fuel supply is still in the running for causes -- some moving eventual partial flow plug as described in other posts recently...just hard to see how any fuel issue "waits 40 minutes" or how it "happens sooner if under greater load." Hmmm, maybe not so far fetched, since with higher loads fuel is being supplied at a faster rate (and might lead to a 20 minute start of disease rather than 40 minute...?) Your dealer or anyone working on it could rig an "IV bag" of fuel and bypass the tank, the lines the filters and cross them off the possible cause list.

Certainly unscrew the fuel filler cap first (the next time it happens) and see if the issue goes away !! That is so easy it is ridiculous and 81 posts later several of us will be outside trying to slap ourselves up side the head harder if that turns out to be the problem ! Embarrassed to say it fits -- a partial vacuum being created in the tank by fuel usage... 1) it would recover after a while with air leaking back into the top of the tank 2) it would take longer to happen under light loads with less fuel flow and 3) sooner to happen with heavier loads and more fuel flow, etc... geeze!

Yes Sir, if this "is" the problem, embarrassing may be a kind word.

It sure is the best answer so far, and it checks all the boxes...
-> Higher/heavier loads consume more fuel creating the vacuum quicker than without a load.
-> A/C on creates the problem a bit quicker, yes, w the air on I've always seen a faster fuel drop, but it's not real major.
-> I've never seen any noticeable engine temp increases, this would be true with a vacuumed fuel starved feed.
-> I let tractor sit for an hour or so, I get another 5-10 minutes of good power. I wait overnight and I have the ~40mins again
-> Changing the HST oil and filters was not a remedy and would not be if the fuel was being starved.

TBC! (Crossing Fingers)

 

[TopSpeed1]

Sadly, the Saga continues...

I was feeling so optimistic that this was going to be the cause, the grass WAS a tad shorter than norm as I did rush this mow job by a day or 2. I did go about 45mins, albeit I didn't have the A/C on. When the sluggishness kicked in, I took the mower and tractor out of gear (kept at idle) and opened the fuel cap. Nothing, I was expecting a vacuum of sorts.

I hopped back on and wound the RPMs back up, I could immediately tell it had some zip so I began mowing again, maybe for 2 minutes then the RPMS started dropping, especially on the tight turns or in higher grass (not that I would classify this as tall grass to begin with!).

So to defiantly rule out the fuel cap, I went in the house and got some tape, unscrewed the fuel cap 99% of the way, so as it was rocking on the plastic threads and plenty of gap now to escape any possible vacuum buildup. Again, same thing, good for a couple of minutes and more sluggish on tight turns or slight up-hills. AC was then put on, with a little more noticeable engine RMP droppage/sluggy-ness.

 

[thclimer]

Well at least you have now ruled out the venting issue. However, it sure seems to be fuel related as you noticed an increase for a minute or 2 which to me seems to rule out a software thermal heat protection mode.

 

[Yander]

Found this thread on another site when doing a google search. Looks like they replaced the Turbo to fix this guys issue..

MF 1735M power loss when it reaches normal operating temp.

www.mytractorforum.com

 

[thclimer]

So I wonder if there is a way you can confirm the turbo is acting up without a laptop?

 

[WranglerX]

Pressure gauge on output side of turbo?

 

[TopSpeed1]

Found this thread on another site when doing a google search. Looks like they replaced the Turbo to fix this guys issue..

MF 1735M power loss when it reaches normal operating temp.

www.mytractorforum.com

Great thread on what seems to be the same exact problem, and I thank you so much for finding this (not sure how I didn't, but way cool!). Only thing is the OP never replied back that it was actually the "fix".

Here's his last post....

Razeandpillage Discussion starter
5 posts · Joined 2021

#7 · Aug 24, 2022
Got called today, they say it's passing the dyno and the turbo seems to of been the problem. Hoping to get it back and see how it does with the finish mower and the brush hog.

 

[TopSpeed1]

I just got off the phone with my dealers service mgr (Aleasha).
She's looking into what should be our next step. I told her that if we could pre-plan this so my tractor doesn't just sit at the dealer for a week or two doing nothing while Agco okay's the warranty replacement, that would be great. My 2 acre yard doesn't like to be put on hold, especially this time of year.

PS; unlike that other Forum's thread on this, I will mark this one as "SOLVED" in the title and ending post, unlike the other Forum thread as it is kinda vague and left hanging. I understand, the guy is now happy and his problem is fixed, but it doesn't help the next guy for an actual conclusion.

 

[JWR]

Your turbo charger is too expensive for AGCO company to throw that guess at the problem. On the other hand, we do not know what all THEY know about the total population of tractors with this disease. Just as a tech issue (independent of the $ advisability of trying a new turbo) I am puzzled by how a turbo would wait 40 minutes to do anything (or less time under heavier load.) I'd certainly try the "IV drip bag fuel source" first. Might be something floating in fuel tank or lines that takes a while to clog (?) Maybe fuel flow quantity related? Any answers so far seem far fetched which is why this whole disease is so baffling.