JD 5100e engine problem. Dealer doesn't know what it is.

[Dadnatron]

I have a 5100e which I've owned 2nd hand since 400hrs or so. It is currently at about 1800hrs and I've used it hard in building my farm.

I've kept up basic maintenance and its ran relatively well. Had a couple minor issues which required going to the shop. The biggest 2 were algae in the tank and breaking a bolt for the FEL, in the tractor frame and being unable to remove it myself.

Last fall, I began getting a 'turn the tractor off immediately' warning light popping on for about 2 sec, then immediately shutting off. It typically occurred when under load and was first noticed while mowing with a 15' HD Woods batwing. At RPMs of about 2500, it would blink on with a warning tone, but then almost immediately go off. I checked codes and had a multitude of them, but the main one seemed to be associated with low fuel rail pressure and similar issues. I'd had this code before and fixed it by changing out the fuel filters. So that's what I did again. It seemed to work for about a day, but the issue almost immediately resumed. At low RPM, everything seems fine and it has normal power. But at higher, 2500 RPM, I get a cutting/surging type effect.

I figured given the on/off warning light, that this was simply a sensor/computer issue. I didn't want to take it in to the dealer, so I called for mobile service. (I have more time constraints than anything else.) He came out and proceeded to change out/check all sensors, low and high pressure fuel pump, and about everything else he could think of. Nothing changed the issue. He contacted JD technical, and they couldn't figure it out. They finally landed on the 'thought' that it might be a fuel injector which at high RPM, is pulling in air, causing the issue. It will cost about $3K to take it in and have them check/change them out. And even then, they aren't sure its the real problem, just that it is the only other thing they can thing of.

It isn't that the computer is decreasing HP to preserve the engine, as it can if there is an issue, but it can still run. They checked over the software and couldn't find anything.

I'm at a loss, they said I can still use the tractor and the issue will not result in further 'damage'. But I have less 'tractor' than I should. At this point, I can still use it about 90% normal. But I hate having this hanging over my head, should I need more power, and simply be unable to access it. I can mow with it in 'e' mode, getting the 540 pto up to speed at lower RPMs, so that isn't the issue.

Any thoughts?

 

[dodge man]

A guess on my part,and you and the dealer probably know, this but it sounds like a fuel problem. The question is what? A couple things come to mind. How sure are you the algae problem is gone? Is there a big chunk of goo that is floating around and blocking the outlet of the tank? The other is the low pressure fuel pump. Is it putting out the flow it’s suppose to?

 

[Dadnatron]

My initial worry was more algae, but the mobile tech took out the tank filter and said it was completely clear.

He spent several days on it, as it was really bothering him. He didn't charge me the full amount because he was flummoxed and couldn't get it fixed.

My 'fear' is that I'll end up taking it in, and they will not be able to address the issue but I'll have a big bill.

I've never changed out a diesel fuel injector... but there is a relatively good mechanic locally who has worked on things before. He is just an old farmer who buys old equipment with issues and refurbishes them then sells.

How hard/worrisome is it to change out injectors? I'm trying to decide whether to have him take a look with the intent of changing them out... or to simply buck up and take it to the dealer. I hate dealers, as I always feel as though I've been reamed when I'm through. But, they might be the only option with this issue.

 

[Harry in Ky]

A quick look at JD parts site for injectors, Central Equipment lists the price at $560 each. Might be different based on engine serial number, but that's a spendy experiment either way.

 

[jd110]

Hard to believe an injector at 1800 hours but anything is possible. I assume he has done all the basics such as checking all rubber fuel lines for dry rot cracks that can cause air to be drawn in system? Also check that they aren't pinched or kinked anywhere. If tank screen is clean and filters are new and fuel transfer pump is pumping too spec, then the next step should be testing for return flow from injectors and return from high pressure pump. excess return flow indicates a bad injector or pump. Unfortunately if excess flow from injectors is found, there is no way to isolate which cylinder has the faulty injector and a full set is recommended. New injectors need to be calibrated which requires the use of the dealers laptop. Low rail pressure can also be caused by a faulty rail pressure relief valve and/or pump control valve(suction control valve)

 

[TractorGuy]

I would start at the tank outlet and work forward. Pull any lines and fittings and clean them out. I wrestled with a fuel problem for two weeks one time and although it had plenty of dirty issues the culprit turned out to be a clogged banjo fitting. Little areas where rust or algae can get trapped can mess with you.

 

[zzvyb6]

A friend of mine had the same problem. The RPM dependency was actually fuel RATE issue. The hose to the injector pump had a worn end and the clamp was no longer tight, allowing air to enter, or pinched line, not sure. New hose made the problem go way. New clamps were the screw type instead of the pinch rings. (Well that's because 1 went flying off into the wild blue yonder when she pulled off the hose).

 

[oldtimer 66]

This is a JD Power Tech engine. It has individual injector pumps for each cylinder, that is the the injector pump is fired by a fuel lobe on the cam shaft/ 4 cylinder engine has 4 fuel lobes on the cam shaft. Therefor there are 4 individual pumps. Lets call it a cam follower fuel pump that supplies hp fuel to each injector. The pumps and injectors are matched sets. I would look at the pressure on the low pressure fuel pump first. Should be on the right side of the engine/ it also runs off the cam shaft with it's own fuel lobe/ I think from memory is 10 PSI minimum. I would pull the line at the low pressure pump to see if you have a good gravity flow from the fuel tank with sufficient fuel in the tank. There are no external lines/ hoses on the fuel system. The only hoses on the system are from the tank to the low pressure pump and then to and from the fuel filter arrangement and then into the engine block. All of the fuel passages are machined internally inside the engine block. That's all I can add to this discussion.

 

[Brown Dog]

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What state are you located ?

 

[Dadnatron]

I'm in Kentucky (Lexington area).

OldTimer 66, the mobile tech changed out all sensors, one at a time and that did nothing. He then changed out the Low Pressure pump (nothing) then High pressure pump (still nothing). He checked the tank and screen and said it was clean. I'd changed out both fuel filters when this began (Nothing) I ran about a gallon of Sea Foam and related 'additives' without change. The thing is, it runs perfectly normal up until about 2500 RPM. He checked the software and spoke with JD technical, and the only thing they could come up with was an injector pulling air at high RPM. They don't KNOW this... it is just their next thought.