John Deere 1600 turbo wide area mower stalls over bumps

[Maintenance Mech]

First post here. I need some help with Our John Deere 1600 turbo wide area mower (WAM). The guy who primarily ran the machine and serviced it for years, has just retired. He was just content to live with it, but the tractor shuts down so much that it is almost to the point of being unusable now. The engine stalls out frequently when the machine goes over bumps in the turf. Slow or fast mowing speed doesn't seem to matter. It also sometimes stalls when going forward or reverse from a dead stop, although this is less frequent and may be a different problem. The main problem however is the bumps. Sometimes it takes a large bump, other times a series of small ones that shake the tractor will shut it down. Originally, I assumed that an over sensitive seat safety was to blame, however I noticed was that I am not always bouncing off the seat at all when this happens. To rule out the seat safety, I temporarily disconnected it, and jumped out the wires. The engine still cuts out just as often. For the record, I only disabled the seat safety for a couple of hours, then reconnected it after it was proved out. At this point, I am thinking that there is a bad wiring connection somewhere, but this thing has a ridiculously over complicated wiring system, and very little is labeled as to what's what. I am hoping that someone has had a similar problem, and can point me in the right direction.

Here is some basic info about the tractor.
2006 John Deere 1600 Turbo WAM series II
~2000 hours on meter
Machine is 4wd
Yanmar Turbo diesel engine 56hp

Recent service that I have performed (the problems existed prior to all of this being done)
Changed hydraulic fluid
Changed transmission fluid
Changed fuel filter, and cleaned sediment bowl
Ran some diesel oil fuel system cleaner through the engine with a fresh tank of fuel.
Adjusted throttle cable slightly as it had slipped and was loose.
Adjusted hydrostatic pedal linkage. The tractor had been traveling slower and slower. I adjusted the travel speed back up to the spec in the manual, as verified by a vehicle driven behind the machine on flat level parking lot.

I am hopeful that someone here can offer some insight into this problem. It has been going on for quite a while, but now that the responsibility has fallen to me, I would like to fix it properly, rather than ignore the problem, as the previous guy did. Thanks for any help you can offer.

 

[hosspuller]

Does the engine immediately restart?

Does the stalling happen with a full tank of fuel?

Have you checked the fuel line "IN" the tank?

Deere has a plastic pick-up line the tank. The tube disintegrates allowing air to enter the system.

 

[Maintenance Mech]

Yes, the engine does immediately restart. It does also stall out even if the tank is full. I am off work until Monday, but will see if I can check the tank then. Due to the way the fuel filler is run to accommodate the aftermarket cab (Boxer), it might be fun trying to get a look in there. If air in the line was the problem, It would seem likely that the tractor wouldn't restart properly, however at this point, I am willing to try just about anything.

 

[hosspuller]

Since the stalling happens when over bumpy ground I'm more inclined to suspect an electrical problem. Start the engine and wiggle connections. Be careful of moving parts. A wooden stick is good to jiggle stuff.

 

[Maintenance Mech]

Ok, I finally got this figured out. I had to Buy a John Deere technical manual to make heads or tails of this thing, then find time to actually test everything. So, one $240 service manual, and one $12 relay later, the tractor doesn't stall over every bump any more. Turns out that the fuel pull in relay was the problem. It must have gotten too weak to hold over the bumps. I appreciate your advice hosspuller. Turns out it was in fact an electrical problem.

 

[Slem]

Ok, I finally got this figured out. I had to Buy a John Deere technical manual to make heads or tails of this thing, then find time to actually test everything. So, one $240 service manual, and one $12 relay later, the tractor doesn't stall over every bump any more. Turns out that the fuel pull in relay was the problem. It must have gotten too weak to hold over the bumps. I appreciate your advice hosspuller. Turns out it was in fact an electrical problem.

I have a 2011 1600 that is doing the same thing as yours was doing. Could you tell me where the relay is located that you replaced?

 

[Maintenance Mech]

We have since replaced the machine, so I will have to go somewhat by memory, although I did find an old pm that someone sent me with the same question. Here is what I wrote to them: The relay was the one for the fuel pull in solenoid. I will try to take a look at the machine tomorrow and figure out which one was the culprit. If I remember correctly, there were three relays. Two are identical, the starter relay, and the fuel pull in solenoid relay. Swapping these two may give you a clue as to whether or not a week relay is your problem. The relay in question was only about 12 bucks through Deere country, and I believe our dealer had them in stock at the time.

That said, we also had some trouble with the seat safety needing adjustment (It's a metal hoop with a contact that's located under the seat cushion, and can be bent slightly to be less sensitive), and the neutral pedal safety switch. This part is located on the underbelly of the tractor near where the hydrostatic pedal linkage attaches to the transmission. The switch went bad, and would stall the tractor with increasing frequency. I found it while attempting to tighten a loose hydraulic connection. It is a two wire plunger type switch, which is nearly impossible to get at to replace. My solution was to jump it out. It is designed to prevent the tractor from starting if you have either of the hydrostatic pedals depressed. When the switch begins to fail, or perhaps gets a buildup of dirt internally, it will intermittently stall the engine. Since we are not that dumb, it hasn't been a problem not to have that particular safety. Oh, and it helps to only mow in low range, as the manual suggests. The engine doesn't usually stall in high range, but the decks will shut down over bumps a whole lot easier, than when mowing in low range. This combination of things has resolved our stalling problems. I will try to get back to you in the next day or so with which relay is which.

And my second message to them: If you pull open the panel with the electronic control module, located on the right hand side of the machine, you will see three or four relays. As you may be aware, they are not labeled. Here is the relay layout as per our technical manual. From left to right: Start relay, Fuel pull in relay, Air pre-heater relay, and (optional) lighting relay. Replacing the fuel pull in relay solved our stalling problems for a while, then we started to experience the other issues mentioned above.

Hope this helps you out. That thing was maddening to try to trouble shout. The dealer didn't have any better luck with it. In the end, I concluded that all of the above issues contributed to the stalling out over bumps. Once every one of those things was corrected, the machine ran normally again. That seems to be the trouble with making a machine overly complicated, especially with electronics being involved. I am really starting to miss the older all mechanical equipment. It was a lot less problematic, and much simpler to troubleshoot if something went wrong. Best of luck. Let me know if you have any other questions.

 

[Slem]

Thank you for the detail on what you had to go through. I found the relay and actually bought two of them at the local Deere dealer. I will replace the old one tomorrow and see if that helps. If not I will follow your other steps and see what happens.
Thanks again


Slem

 

[Wamman]

I want to answer this old thread in hopes of helping someone else.i have an 09 1600 with 1400 hours on it.it would die when I hit a really hard bump.i will spare you all the misdiagnosis.what fixed it was the neutral switch.2 wire sensor under the hydraulic tank.push the forward and reverse pedal and follow the linkage.although not recommended I jumped the two wires together from under the seat
With the rear panel removed.it is back toward the back almost to the engine.that fixed it.no more dyeing thank goodness.that sensor
Is buried big time.but the wires aren’t too bad.

 

[Donald NZ]

I have been doing CPR to a 2005 JD 1600 turbo purchased recently.
There have been many problems I have worked through

I have fixed all of the problems so far and am yet to fully understand the transmission linkage assembly.

The machine will achieve about 30 % fwd and 1 % backwards travel speed. Pushing down on the linkage with a broom handle behind the seat right side it achieves much closer to full speed.

Does anyone have a schematic or set up information. I purchased a on line manual , unfortunately this only shows how to adjust an eccentric cam to make a small adjustment to the neutral position.

Kind regards