John Deere Gator Forums banner

1 - 20 of 27 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
Howdy, Our HPX 4X4 Diesel starts runs for a while then dies. Hot or cold.
This is easily repeated over and over.
It has new glow plugs, and fuel shut-off solenoid.
Put a test light connected to the hold-in wire (yellow) and the black wire, on the solenoid side of the X3 connector to test voltage to solenoid.
Test light on solid every time it dies. No loss of power to solenoid.
Ran jumper wires direct from battery, to solenoid, and engine runs perfect.
Ran jumper wires from battery to a new accessory relay, to the solenoid, and ran vehicle switch ignition circuit to operate the relay. Dies.
Ran direct wire from ignition switch (yellow) to X3 Solenoid connector. Dies.
I'm really stumped.
Ideas?

T.....
 

·
Registered
Joined
·
763 Posts
I'd clean the fuel lines, tank and the inlet to the fuel filter to make certain there isn't any obstructions. Bacteria can grow in diesel fuel and create a lot of problems.

When I suspect a fuel issue, I make certain to verify the fuel is clean and there is unrestricted flow from the fuel line. Clean white bucket makes makes it easy to check for fuel contamination.

A very thorough inspection of the fuel lines, including the pickup tube to make certain there are no small cracks.

Report back what you find.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #3
I've already checked the fuel line on the supply side of the lift pump by drawing fuel with a very large syringe.
Fuel flowed easily with no bubbles.
I've also installed a new lift pump.
What bakes my noodle is that if I run a wire straight from the battery, it runs.
If I run a wire straight from the ignition switch, it dies.
 

·
Registered
Joined
·
198 Posts
I'm wondering if your solenoid and relay are similar to the 855/865. There is power to the solenoid, power to a relay terminal for starting, and power to a "stay open" terminal for when the starting switch is let go to run. If I understand your description of the voltages being hot on the proper terminals at the proper time, it leads me to believe the relay block is bad. It sounds like your engine runs by bypassing the momentary starting line to keep it hot all the time. I suspect the stay open coil is the culprit.
 

·
Super Moderator
Joined
·
2,659 Posts
From the OEM Technical Manual, I realize you have been working through some electrical testing. PM me for more information from the Technical Manual.





Good luck
 

·
Registered
Joined
·
14 Posts
Discussion Starter #6
Thanks for the replies...
I have the TM2195 Jan. '06 Technical manual, Thanks for the reference material
I have worked through appropriate flow of diagnosis, but due to the fact that if I wire the battery direct with jumper wires, it will operate perfect and run all day long.
But if I run a direct wire from the ignition output wire, bypassing all electrical components except for the ignition switch, it will randomly die.
This leads me to believe that the new Fuel shutoff solenoid takes more amps than is being supplied by the Ignition switch alone.
Sounds weird, since most fuel shut-off solenoids don't draw very many amps. Especially the Hold-In coil.....
I am going to run fuel from a separate container, to rule out any fuel tank issues, like maybe a floater that will occasionally block the inlet... Dunno...
 

·
Super Moderator
Joined
·
2,659 Posts
Thanks for the replies...
I have the TM2195 Jan. '06 Technical manual, Thanks for the reference material
I have worked through appropriate flow of diagnosis, but due to the fact that if I wire the battery direct with jumper wires, it will operate perfect and run all day long.
But if I run a direct wire from the ignition output wire, bypassing all electrical components except for the ignition switch, it will randomly die.
This leads me to believe that the new Fuel shutoff solenoid takes more amps than is being supplied by the Ignition switch alone.
Sounds weird, since most fuel shut-off solenoids don't draw very many amps. Especially the Hold-In coil.....
I am going to run fuel from a separate container, to rule out any fuel tank issues, like maybe a floater that will occasionally block the inlet... Dunno...


You’re most welcome!! Please keep us updated on your progress.

I wonder if you can determine the amp draw on the new fuel shutoff solenoid vs the older type or part number?
 

·
Registered
Joined
·
14 Posts
Discussion Starter #8
OK. I was going to wash my hands of the problem, and run a fused wire from the battery + to a lighted rocker switch in the available dash location, to the fuel shut-off solenoid, since a hot wire to the solenoid straight from the Batt+ worked.
Turns out, adding a switch into the circuit, makes it die as well.
Crap.
So I am suspecting that the new fuel shut-off solenoid Hold-In Coil is faulty, and checked resistance from chart in Tech Manual page 350.
Here are the results:
Correct Ohms Resistance from Chart
Black/White = 0.4
Black/Red = 12
Red/White = 12.4
Current Ohms Resistance from Solenoid
Black/White = 0.5
Black/Red = 34
Red/White = 34.4
Looks like high resistance from Hold-In Circuit (Red)
Might explain why full, uninterupted battery voltage is needed to keep running.
Will try another new solenoid.
What do you think?
T....
 

·
Registered
Joined
·
763 Posts
When buying electrical parts that can't be returned, I test them before paying for them. Usually get a strange look when doing so, but have found not all new parts are within specs.

What did the old solenoid measure?
 

·
Super Moderator
Joined
·
2,659 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #11
We inherited the problem gator from Parks & Rec. and it came with the new parts in it already, being the John Deere dealer here threw all the new parts in it, and also put a new fuel filter in it, upside down, without the spring below it. So the filter sat on the bottom of the sediment bowl, and kind of spun around and around as the engine ran.
Then returned the Gator with the Bill and the problem not fixed.
We don't use that John Deere dealer anymore.
----------------------
Readings for the Solenoid tests were:
----------------------
Correct Ohms Resistance from Chart
Black/White = 0.4
Black/Red = 12
Red/White = 12.4
----------------------
Current Ohms Resistance from Solenoid
Black/White = 0.5
Black/Red = 34
Red/White = 34.4
 

·
Registered
Joined
·
14 Posts
Discussion Starter #12
OK. Got the new fuel shut-off solenoid, and tested the resistance before installing it.
Same reading as one currently in Gator.
Crap.
Looks like the manual is off, or parts can vary in Ohms resistance.
Looks like we get to eat a $40 part.
Might as well install it and see what happens..
The saga continues...…...
 

·
Registered
Joined
·
763 Posts
Terry Bush,

I've had similar experience when dealing with electrical parts and specs listed in workshop manuals, hence my recommendation to test at time of purchase. I even take the manual along and show them the new part doesn't meet published specs, so I have some recourse for refund/replacement.

When the gator dies does it die instantaneously or does is die slowly (relatively speaking) and both will happen quickly.

When dealing with wiring, I've gone through the pain at times of completely disassembling the connectors, so the metal components could be sanded clean and ensure the mating metal parts are well connected. At times the plastic terminal housing can hide poor metal connections/continuity. Don't trust any electrical connection.

You'll know the root cause is found when you can turn the problem off and on multiple times.

Don't rule out a fuel issue. They can be tricky to diagnose and difficult to find the root cause. Sometimes the contaminants are found in the filter housing itself where the fuel enters or in the manual fuel shutoff.

Although frustrating, I have confidence you'll find the issue.

Good luck
 

·
Registered
Joined
·
14 Posts
Discussion Starter #14
Back to the drawing board....
The new solenoid is in, and it only runs for a minute or two, then shuts off. Like turning the ignition switch off. Just dies. No stumbling, just shuts off.
If it were a fuel problem why would it run forever on a straight, uninterrupted 14 gauge wire from the battery?
Freakin' weird...
There is a module up front, but I think that's for the fan, 4x4, and start relay (for the starter)
I'll re-visit the fuel supply, and since the lift pump, shut-off solenoid, and filter are all new, and I installed them, I will look for fuel problems upstream from there.
I don't know if a faulty oil pressure switch will kill the engine, and would have to do so via the fuel solenoid. and the solenoid never loses power or ground, when it dies.
I cannot locate the "S-2" connection point that at least 8 wires splice together.
Time for the rubber hammer treatment... LOL!
 

·
Registered
Joined
·
763 Posts
OK. I was going to wash my hands of the problem, and run a fused wire from the battery + to a lighted rocker switch in the available dash location, to the fuel shut-off solenoid, since a hot wire to the solenoid straight from the Batt+ worked.
Turns out, adding a switch into the circuit, makes it die as well.
Crap.

T....
In some deductive root cause methodologies it is necessary to turn the problem off/on 5x to prove the root cause is found. This rules out coincidence causing one to go down the wrong solution path. I'm not saying this is your issue, but it does sound like you have conflicting results about a direct wire feed solving all run issues.

It would be easy enough to wire a temporary light to the run solenoid to see if the voltage drops from the circuit momentarily.

Don't rule out my earlier suggestion to remove the wire terminals from the plastic housing to make certain there is unimpeded electrical contact. This holds true for the terminals inside the fuse box on this circuit. Most connections are the male/female tab and it is very easy for there to be insufficient grip between the two metal parts. I've also seen corrosion at the crimp end of the terminal creating issues. It's not like they use automotive grade weather pack connectors.

I don't have the manual for you machine, so it is difficult guessing what transfers from the 855D manual to your machine..

While it seems your focus has been on the power supply side, don't forget to pay close attention to the ground. Wire connections can "look" good, but until you know the metal surfaces are clean and can prove the joint conducts without any losses, it should be assumed bad.

A voltage drop test may prove useful, but his may yield minimal results given the low current draw on this circuit.

It might be worth purchasing the workshop manual to better understand the wiring circuit. They are expensive, but you are putting a lot of effort into the situation and unnecessary parts.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #16 (Edited)
200mph, thanks for the advice....
went through the upstream fuel components, removed and cleaned the filter base assy., put new fuel lines in all engine components, ran fuel from an isolated fuel container to rule out OEM fuel tank and supply/return lines.
Still dies.
I have ruled out a voltage drop to solenoid by running a test light between the Red, Hold-In circuit, and the Black ground wire, on the solenoid side of the connector, so to test everything upstream of the solenoid. Voltage was constant, even when it dies. No drop-outs.
Every test has been repeated several times to rule out a fluke.
Called a JD Dealer in Longview, to have them look at it, and, after seeing my testing and results, suggested trying a Thermistor at the shut-off solenoid connector, to allow more amperage to be delivered to the solenoid. Kind of like me running 14 gauge wire from battery to Solenoid with an accessory relay switched by the ignition switch, which didn't work either. Neither did running a wire direct from ignition switch to solenoid.....
At this point, I'll try anything!
Should get the part tomorrow, I will update....
 

·
Registered
Joined
·
763 Posts
Just trying to learn something here...
I'm a bit confused how a thermistor increase power to the solenoid. Typically a thermistor is nothing but a resistor that is dependent on temperature by a much greater degree versus a normal resistor. If you get a clear description on how this improves the situation, I would like to learn about it... Perhaps I could use this idea in other situations. Thermistor and diodes are typically used in relays to protect the high voltage spike that occurs when the solenoid is deenergized.


Just trying to help...
Did you take apart the aluminum section of the fuel filter, disassemble and thoroughly clean the passages? To do so will require taking the shutoff lever out of the housing? It sounds like from your description the focus was on the filter and bowl. I'm suggesting a much deeper cleaning. Pointing this out as I and others have found stuff in this area before. See attachment item A & B.

I'm not aware of anything else in the circuit that would cause a problem your describing. If fuel solenoid is allowing fuel flow and the fuel is clean it should run 100% of time.

I'll page through the 855D technical manual when time allows, but its a guess if anything in it is applicable to your gator.

Edit #2: The ohm values in the 855D manual state 24 +/-10% for what it is worth.

There is also a blurb about how the VCU times the two positions of the fuel shutoff solenoid during operation. But remember this is on a 855D.
 

Attachments

·
Registered
Joined
·
14 Posts
Discussion Starter #18
200mph, I am as confused on how a thermistor could help, being that I ran 14 gauge zip wire direct from battery to solenoid, through a 40 amp accessory relay, energized by the ignition switch, which didn't work.

Last night, I ran the engine for a half an hour, with a jumper wire from battery to the solenoid, just to charge up the battery, and to double check that I'm not going crazy.... LOL...

I did take the fuel filter housing assy. off, and disassembled it on the bench, and cleaned everything with brake clean, and blew it out with shop air. and replaced the two fuel lines that run from filter to injector pump and the return hose as well.
one of the hoses was worn almost through, which made me pee a little, but alas didn't make any difference. haha...

Hopefully the thermistor gets here today, and I can have another disappointment.
 

·
Registered
Joined
·
763 Posts
Thanks for posting the P/N and link of the thermistor.

It will be interesting to see what they find.
 
1 - 20 of 27 Posts
Top