JD X749 Dying after 30-45 minutes

[Mike VS]

Any chance there is a line that gets soft when heated and collapses under vacuum? This could also apply to the air intake system.

I got out this morning and tested that flow while sitting in the seat. Zero effect, and it is POURING out of the hose. I also disconnected the air filter sensor to see if it is heating and shutting it down. I looks like a normally open switch and I am not sure if it gives a warning or shuts the engine off.

 

[Mike VS]

Do you mean to the injector pump from the tank, or is this a return line?

I don't think the transfer pump is a fragile item. I wouldn't hesitate to open it up to check the insides. You're running out of options on this to the point that the injection pump will be all that is remaining.

Well I disassembled the transfer pump... absolutely pristine inside. It's back together and running without a leak. You were right, no problems with the gaskets.

 

[crazyal]

I assume that the fuel goes from the pump you've opened up to the injector pump. If so I think I might add a pressure gauge right before the injector pump. There shouldn't be much pressure but it'll tell you if when it dies if the same pressure is there. If so then you might need to look at the injector pump. Since the time it takes to happen doesn't seam random I don't think there's something floating around in your tank that works it's way over to the outlet but at some point I think I would pull the tank and verify it.

 

[Mike VS]

I was going to post this yesterday, but didn't get around to it.
Now that you've pulled the transfer pump, you'll have to check the oil level in the injection pump.

View attachment 660586

Lovely... I didn't know there was an oil level to check. I've run it after putting the pump back on. Not much motor oil came out of the pump. I'll check the drawing you sent.

Also, as stated I ran it afterwards but this time it ran for 90 minutes without failure. It has never gone over an hour without dying so I'm holding my breath until next weeks cutting. The only change was opening the transfer pump and reassembling (I swear it was as clean as new). I also disconnected the wire harness from the air filter box. I don't know if a dirty filter kills the engine or sends an alarm but it seems to be an open switch that allows me to disconnect without killing the engine. I figured that if it is supposed to kill the engine, maybe it is overheating and failing. Time will tell if it's even fixed.

UPDATE: After looking at the diagram it looked very much like my pump. The directions are very clear as to where to ad oil and waiting for it to run out of the disconnected oil pipe below.
Now the reality of what happened: Looking inside the pump from the oil plug I could not see any oil which freaked me out. I started adding oil but nothing was coming out of the lower hole. After about 16 oz. I knew something was wrong and checked the motor oil level. All the oil is going into the engine and had to be drained. What am I doing wrong or does this pump get it's oil from the engine?

 

[Mike VS]

I assume that the fuel goes from the pump you've opened up to the injector pump. If so I think I might add a pressure gauge right before the injector pump. There shouldn't be much pressure but it'll tell you if when it dies if the same pressure is there. If so then you might need to look at the injector pump.

Not a bad idea.

 

[ruffdog]

UPDATE: After looking at the diagram it looked very much like my pump. The directions are very clear as to where to ad oil and waiting for it to run out of the disconnected oil pipe below.
Now the reality of what happened: Looking inside the pump from the oil plug I could not see any oil which freaked me out. I started adding oil but nothing was coming out of the lower hole. After about 16 oz. I knew something was wrong and checked the motor oil level. All the oil is going into the engine and had to be drained. What am I doing wrong or does this pump get it's oil from the engine?

I would ASSUME that the injection pump does get it's oil from the engine and just holds a small reservoir to use and any extra flows back to the engine sump. Being that the transfer pump is mounted lower than where they want the oil level to be, they just want the owner to top it off before running. Just get the engine oil level correct and run the heck out of it. Just let us know if it fixed the problem!

 

[Mike VS]

I would ASSUME that the injection pump does get it's oil from the engine and just holds a small reservoir to use and any extra flows back to the engine sump. Being that the transfer pump is mounted lower than where they want the oil level to be, they just want the owner to top it off before running. Just get the engine oil level correct and run the heck out of it. Just let us know if it fixed the problem!

If you look at the diagram that E7LN provided it spells out that there is a separate oil level and how to check it. While that diagram looks just like my injector pump, it (hopefully) provides it's oil different than mine.
I wont be running it again until next week, I cut every blade of grass within a half mile testing it today!

 

[Mike VS]

That question, I can't answer, but I've seen the same comments in different tech manuals.
Maybe your overflow tube is plugged, or they simply want some oil added so you don't start dry.

I'll cross my fingers and run it.

 

[Mike VS]

I'm at the end of my rope. After cutting for 62 minutes yesterday, it died again. Other than checking the fuel pick up in the tank I have tried everything without success, and even that seems fine considering the amount of fuel that flows freely from gravity.
The odd thing about it is that it runs flawlessly until it suddenly dies. I would think that some sort of fuel blockage would result in a loss of power that I would feel. It looks like something I'll have to live with until it dies permanently.

 

[Kyle_in_Tex]

so when it dies, can you re-start it immediately?