2012 L4240hstc-3 cold start concern

[dfixit1]

Yes on start up.

Once your GP circuit is working as it should, you'll be amazed at how fast it starts and you'll be upset that Kubota made this mistake in the first place or didn't issue a recall to have it corrected.

Thanks for the complement on the write up.

You’re welcome, I will check mine tomorrow.
I wonder if they carried over this issue into the 60 series? I have two friends that have them and one told me his started and smoked like mine.

 

[dfixit1]

I pulled the dash cover and instrument cluster to access the glow plug relays.
Pulled one of the suspect connectors and checked it with the relay, didnt seem tight enough but not loose either. Grabbed a solderless connector and used a micrometer to check the thickness. It was .01 thicker. Tested the remaining three connectors. Loose!

Made wire inserts out of .010 wire instead of paper clips.

Added Power Service and topped off tank with winter fuel.

Started and it still had some white smoke but not as bad as before but it was hitting on all four cylinders!

Ordering relays from Amazon.

Thanks!

 

[troverman]

Cool! Glad you figured it out.

 

[200mph]

Did your relay have the 1/4" wide tabs?

What relays did you order?

Glad you're up and running.

 

[dfixit1]

Did your relay have the 1/4" wide tabs?

What relays did you order?

Glad you're up and running.

Yes they had 1/4 tabs but back to the drawing board.
Left it outside today and it acted up again. I need to get a shop manual to check out the GP circuit. :-(
Must have been a fluke this morning.
Didnt order yet, I was planning on getting the same ones you linked on Amazon.

Talked to my dealer (out of state) and had him search for a TSB but couldn’t find one. He asked his mechanics how they repair them and the cut the plugs off and install the correct size connectors.

 

[dfixit1]

Went back to basics, cleaned battery connections, removed slow blow fuses and checked connections, cleaned ground to frame and used carbon grease sparingly on connections to promote conductivity.
Checked battery voltage 13.03V
But it was dropping after several voltage tests 12.4-12.6V
Checked voltage at relays, within .2V
Checked white GP connector unplugged within.2V of battery.
Checked white connector plugged in with relays ON for GP before cleaning connection 8.6+V
After 9.5-10V depending on how many cycles. It would slowly raise on multi cycles in a row.
Does anyone know the spec on the voltage drop for the GP?

I have no way to test the battery load or cell condition. I believe its the original.
I wonder if its weak and dropping voltage with the draw of the GP?

Found this video on my model.
https://youtu.be/_UmLWJiEC9w
Relay part number RD451-54210 (this has the 3/8 inch wide spade terminal)

https://www.messicks.com/part/rd451-54210/relay-40a-iso

According to the video, the one on the right (sitting in the seat) is the stop relay. The left is the GP relay.
I just swapped the two on mine but didnt see any blueing on the terminals or bubbling of plastic.

 

[dfixit1]

Went to my local Kubota dealer and purchased the updated relay, it was $28.
Talked to a mechanic and showed him my video on a cold start. He asked which model of Grand L-4240hstc? Mine is the 3rd model.
He stated the start with white smoke and stumbling was normal due to emissions on my model, egr, timing etc. He stated EPA specs are for warmed up engines.
He said the only way to have better cold starts is with a block heater.

 

[troverman]

Went to my local Kubota dealer and purchased the updated relay, it was $28.
Talked to a mechanic and showed him my video on a cold start. He asked which model of Grand L-4240hstc? Mine is the 3rd model.
He stated the start with white smoke and stumbling was normal due to emissions on my model, egr, timing etc. He stated EPA specs are for warmed up engines.
He said the only way to have better cold starts is with a block heater.

I don't think your dealer is being honest or perhaps not knowledgeable. My L4060 starts really well after the glow plug light goes out, with only some vapor emitting from the exhaust. Engine is smooth.

Change out the relay and let us know if it runs / starts better.

 

[D2Cat]

I think I'm going to change out the relays in my L4240 just to see if there is a difference. It starts fine, but it may start better!!

 

[200mph]

Went to my local Kubota dealer and purchased the updated relay, it was $28.
Talked to a mechanic and showed him my video on a cold start. He asked which model of Grand L-4240hstc? Mine is the 3rd model.
He stated the start with white smoke and stumbling was normal due to emissions on my model, egr, timing etc. He stated EPA specs are for warmed up engines.
He said the only way to have better cold starts is with a block heater.

You should have that person point out where the EGR is on your tractor!
I'd be a bit worried to have this mechanic working on my -3 tractor.

Can you post the video or link in this thread?

It's a shame they charge so much for a non-sealed relay without any built in circuit protection. That is why I posted the link to the relays I purchased in the other link. Plus they handle more current. https://www.amazon.com/gp/product/B07GX6SXY2/ref=ox_sc_act_title_1?smid=A16HAOC7J321VG&psc=1

Did you buy the relay?... If so, let us know how it works.

 

[dfixit1]

Sorry, I dont have a way of posting a video.

No one can seem to answer the voltage drop with the GP energized?

With my battery fully charged Im seeing about 10V at the white harness connector above the fuel filter.

Yes I installed the relay. Didnt seem to change anything.

So far Ive added Power Service white bottle.
Cleaned all connections.
New relay
T6 5w40
Had battery load tested & charged it.
Checked voltages.

 

[200mph]

Can't find the the voltage drop specs your seeking in the WSM. I'm under the impression the GP resistance changes as it heats up, so the voltage would change. If I get a chance, I'll try testing the voltage on my tractor.

Is that 10 volts with the connector connected or open?

WRT Picture: That seems like a lot of smoke. My L4740-3 doesn't smoke like that on startup.

Have you done a compression check? If so, what were the readings?

 

[dfixit1]

Can't find the the voltage drop specs your seeking in the WSM. I'm under the impression the GP resistance changes as it heats up, so the voltage would change. If I get a chance, I'll try testing the voltage on my tractor.

Is that 10 volts with the connector connected or open?

WRT Picture: That seems like a lot of smoke. My L4740-3 doesn't smoke like that on startup.

Have you done a compression check? If so, what were the readings?

Yes the 10V was with it connected.
It doesn’t use oil, runs great. Didn’t do a compression check. I’m thinking with such low hours it’s fuel, GP issue but who knows.
The picture is a screenshot of the video with the worst of it. I watched a Kubota dealer YouTube video where he went through the whole lot in middle of winter starting his inventory. Some looked similar to mine but ....most puffed slightly.

 

[troverman]

Does it smoke like that immediately after startup or maybe 30 seconds after it first started?

Is your coolant level OK? (Just to rule out a headgasket issue, which is unlikely).

One test that might be helpful is using an infrared heat gun. When your tractor is dead cold, aim the gun at each cylinder while an assistant turns the key to activate the glow plugs. This way you can determine if each glow plug is heating about the same or not.

I wish we could see the video...

 

[dfixit1]

Does it smoke like that immediately after startup or maybe 30 seconds after it first started?

Is your coolant level OK? (Just to rule out a headgasket issue, which is unlikely).

One test that might be helpful is using an infrared heat gun. When your tractor is dead cold, aim the gun at each cylinder while an assistant turns the key to activate the glow plugs. This way you can determine if each glow plug is heating about the same or not.

I wish we could see the video...

No it’s not a head gasket. It doesn’t used coolant runs perfectly when it warms up.
I believe it’s fuel related.
I wish this forum would allow posting of videos.
I could email it, I just don’t have a way of posting it.
Regards

 

[troverman]

Guys, dfixit emailed me the video. He operates the glow plugs then starts the tractor. It starts but runs very rough and belches out white fuel smoke. The video is short and doesn't reveal whether the tractor eventually smooths out.

In my opinion, the glow plugs are not working, or not working correctly, assuming the tractor engine smooths out after 30 seconds to a minute or so, depending upon how cold it is out...

 

[dfixit1]

Guys, dfixit emailed me the video. He operates the glow plugs then starts the tractor. It starts but runs very rough and belches out white fuel smoke. The video is short and doesn't reveal whether the tractor eventually smooths out.

In my opinion, the glow plugs are not working, or not working correctly, assuming the tractor engine smooths out after 30 seconds to a minute or so, depending upon how cold it is out...

Yes it smooths out in 20-30 seconds?
Just tested GPs with block at 65 degrees.
.5, .4, .5, .5 ohms in order 1-4.

200 mph suggested specs were .9 ?

Going to reassemble because I need it for snow removal.

Found this
Thats it. No need to pull glow plugs. My understanding is it is physically impossible for plugs to not get hot if they are drawing the right amount of amps. I'm interested in the physics behind this and why the resistance check is not always accurate. With Ohms law -- V(oltage) = I(amps)R(esistance) or I = V/R means 12.5V / .8 ohms =15.7 amps a glow plug draws. If you measure a glow plugs R and it is within range and you have V , why would you not get Amps?
https://www.peachparts.com/shopforum/diesel-discussion/288970-best-easiest-way-test-glow-plugs.html

My meter is a RS true rms digital volt meter. I trust it. It zeros when the leads are connected.
Battery volts 13.3V / .5=26.6A
But 13.3V / .4=33.25A
It would seem the one is drawing too much current.

 

[200mph]

Sent private message.

 

[dfixit1]

Sent private message.

Sent you one too.

 

[dfixit1]

There are a few in this video that are similar to mine starting with unburned fuel.
3rd and 5th ones in.
https://www.youtube.com/watch?v=aaT6cUVAidg