DK45SC Starting problems

[grsthegreat]

When you turn the key, do you hear the snap of the stop solenoid?

 

[rd_macgregor]

When you turn the key, do you hear the snap of the stop solenoid?

Well, I wouldn't call it a "snap"..."click" is more like it. My doubts about the solenoid being the problem concern the intermittancy; if the solenoid (or related relay) are faulty, wouldn't it fail to start, period? As it is, the engine cranks over for a while without starting, then after a few tries (with maybe a few pumps on the filter primer gizmo), it fires right up...and runs fine. If I shut it off, after it is warmed up, then try to start it again, it is back to turning over without evidence of ignition (not even a kick or cough).

 

[jimglassford]

I posted the same problem on my DK55. That is why I am questioning the fuel lift pump. If a check valve is leaking, the fuel runs out of the fuel line. Cranking pumps the fuel again but takes time to get back to the injection pump. This is just a theory and no one has replied to my post yet.

 

[grsthegreat]

Well, I wouldn't call it a "snap"..."click" is more like it. My doubts about the solenoid being the problem concern the intermittancy; if the solenoid (or related relay) are faulty, wouldn't it fail to start, period? As it is, the engine cranks over for a while without starting, then after a few tries (with maybe a few pumps on the filter primer gizmo), it fires right up...and runs fine. If I shut it off, after it is warmed up, then try to start it again, it is back to turning over without evidence of ignition (not even a kick or cough).

actually, no. I had intermittent start issues with mine. Laster for 4 months. One day it wouldnt start, i manually moved the stop rail by unbolting it. Fired right up, had to reinstall it to stop tractor. Replaced stop unit and no issues for years now. I replaced the relay first...no difference.

 

[Kioti Paul]

My DK45 has 3 wires that go to the fuel solenoid, Black, Red, and Blue. The Black wire is ground, the Red wire is 12 volts positive anytime the "ign" switch is on. The Blue wire is 12 volts positive for about 3 seconds any time the "ign" switch is turned from off to on, and is powered from one of the three relays located on the fuel tank heat shield.

The Red and Black wires form a circuit which "holds" the solenoid engaged anytime the "ign" is on. When you turn the "ign" to the off position, the circuit is killed, and the solenoid de-energizes allowing the spring loaded rack to move the injector pump pistons to the stop position. This 'Red and Black" circuit is strong enough to hold the solenoid plunger in the "On" position, but not strong enough to move the plunger into position.

When you turn the "ign" switch from the "OFF" position to the "ON" position, a timer circuit energizes a relay, which, in turn energizes the Blue wire, which, along with the Black wire forms a second circuit, which develops a much stronger magnetic field forcing the solenoid plunger into the "RUN" position. This circuit is only active for a few seconds, because it would eventually over heat.

When you say "after a few tries, it fires right up"; Are you turning the "ign" switch "OFF" between tries?? Or are you just going between "start" and "on" with each try?? If you never turn the switch to the "OFF" position between "tries", then your symptoms have me baffled!

If you ARE turning the ign switch OFF between tries, then I would feel confident that your 'gremlin' is an intermittent problem in the "Blue and Black" circuit. From what I have gleaned from reading posts over the years, the overwhelming majority of the times it has been the Relay. A relay is just a set of switch contacts that is operated by an electromagnet. The contacts absolutely can 'sometimes' make the connection, and 'sometimes' NOT make the connection.

It should not be any problem tracing out the circuit using nothing but a test light, or voltmeter.

When (IF) you have the tractor running again, try shutting it off using the lever located just above the "stop solenoid" NOT BY USING THE IGN SWITCH...KEEP THE IGN SWITCH ON! After the engine dies, I would predict the engine will easily re-start (IF you do NOT turn the switch off). If your tractor has a manual transmission, you could also kill the engine by shifting into High range, 4th gear, at idle, then releasing the clutch while holding the brake.

Good Luck!

 

[grsthegreat]

My DK45 has 3 wires that go to the fuel solenoid, Black, Red, and Blue. The Black wire is ground, the Red wire is 12 volts positive anytime the "ign" switch is on. The Blue wire is 12 volts positive for about 3 seconds any time the "ign" switch is turned from off to on, and is powered from one of the three relays located on the fuel tank heat shield.

The Red and Black wires form a circuit which "holds" the solenoid engaged anytime the "ign" is on. When you turn the "ign" to the off position, the circuit is killed, and the solenoid de-energizes allowing the spring loaded rack to move the injector pump pistons to the stop position. This 'Red and Black" circuit is strong enough to hold the solenoid plunger in the "On" position, but not strong enough to move the plunger into position.

When you turn the "ign" switch from the "OFF" position to the "ON" position, a timer circuit energizes a relay, which, in turn energizes the Blue wire, which, along with the Black wire forms a second circuit, which develops a much stronger magnetic field forcing the solenoid plunger into the "RUN" position. This circuit is only active for a few seconds, because it would eventually over heat.

When you say "after a few tries, it fires right up"; Are you turning the "ign" switch "OFF" between tries?? Or are you just going between "start" and "on" with each try?? If you never turn the switch to the "OFF" position between "tries", then your symptoms have me baffled!

If you ARE turning the ign switch OFF between tries, then I would feel confident that your 'gremlin' is an intermittent problem in the "Blue and Black" circuit. From what I have gleaned from reading posts over the years, the overwhelming majority of the times it has been the Relay. A relay is just a set of switch contacts that is operated by an electromagnet. The contacts absolutely can 'sometimes' make the connection, and 'sometimes' NOT make the connection.

It should not be any problem tracing out the circuit using nothing but a test light, or voltmeter.

When (IF) you have the tractor running again, try shutting it off using the lever located just above the "stop solenoid" NOT BY USING THE IGN SWITCH...KEEP THE IGN SWITCH ON! After the engine dies, I would predict the engine will easily re-start (IF you do NOT turn the switch off). If your tractor has a manual transmission, you could also kill the engine by shifting into High range, 4th gear, at idle, then releasing the clutch while holding the brake.

Good Luck!

my 2010 model year does not have a manual lever at the stop solenoid. wish it did.

 

[Kioti Paul]

my 2010 model year does not have a manual lever at the stop solenoid. wish it did.

THAT'S what stood out to you from my 1/2 dozen paragraphs?? I do see that my last paragraph would not help anyone without a manual cutoff lever AND a hydrostatic transmission.

Actually, I was under the impression your problem had been fixed by a new solenoid, I was trying to offer rd_macgregor (and also - maybe- jimglassford) an idea on something to test. Of course, it seems like Kioti significantly changes designs 'mid-stream', so it's entirely possible my suggestion was completely irrelevant to them also. Coincidentally, the wiring diagram in the Service Manual I purchased from Kioti (at the same time I bought my DK45SC) shows a completely different circuit for the fuel solenoid than what is on my tractor!

 

[LouNY]

THAT'S what stood out to you from my 1/2 dozen paragraphs?? I do see that my last paragraph would not help anyone without a manual cutoff lever AND a hydrostatic transmission.

Actually, I was under the impression your problem had been fixed by a new solenoid, I was trying to offer rd_macgregor (and also - maybe- jimglassford) an idea on something to test. Of course, it seems like Kioti significantly changes designs 'mid-stream', so it's entirely possible my suggestion was completely irrelevant to them also. Coincidentally, the wiring diagram in the Service Manual I purchased from Kioti (at the same time I bought my DK45SC) shows a completely different circuit for the fuel solenoid than what is on my tractor!

Quite often the start coil is only energized with the starter cranking circuit and drops out with the switch to run.

 

[Kioti Paul]

Quite often the start coil is only energized with the starter cranking circuit and drops out with the switch to run.

It would make a lot of sense to me to do that - run a circuit from the starter solenoid to the fuel solenoid; and I suppose a lot of tractors do just that.

My DK45SC is a 2008 year model, and the OP's DK45SC is a 2006 model, so I figure there is a pretty good chance they are wired the same (although, admittedly there is no guarantee), and my tractor does not use the starter's circuit at all for the fuel solenoid.

 

[rd_macgregor]

Thanks for the suggestions and speculations. My 2006 DK45 has the lever by the solenoid...I always wondered what it was for! I have a few things to try out. The past few times I've started the tractor, I've pumped the plunger on top of the fuel filter 8 or 10 times and the engine started on the first try (this may or may not be related, given how intermittent the issue has been in the past.
Finally, jimglassford, is your fuel tank below the engine, then? Mine is on top of the engine just forward of the firewall.