B2400 slow to start on first start.

[Jag3350]

B2400 is puffing white smoke and slow to light off on first start. Will start after about 30 seconds with glow plug activation. All starts after that are fine.
Engine just re-ringed. Compression 400 PSI, injectors cleaned, injector pumps re-oringed, new battery and starter.
Thoughts?

 

[SDT]

B2400 is puffing white smoke and slow to light off on first start. Will start after about 30 seconds with glow plug activation. All starts after that are fine.
Engine just re-ringed. Compression 400 PSI, injectors cleaned, injector pumps re-oringed, new battery and starter.
Thoughts?

Engine hours?

Condition of glow plugs?

Not sure what you mean by "injectors cleaned." Were they rebuilt, replaced, tested?

Cranking speed and compression are crucial.

SDT

 

[BruceP]

I would focus on the glow-plugs:
*) Resistance test each one individually (no need to remove GPs, just disconnect wire and test inplace)
*) Validate all wiring/connections to GPs is clean/tight (loosen/re tighten EVERY connection)
*) Check voltage at the GPs while glowing

Dont be afraid to glow up to 90 seconds in colder ambient temperatures.

 

[85Hokie]

I too would suggest looking at glow plugs again - you are not getting the chamber hot enough to burn the diesel to full combustion. Pump alignment sounds as a possible cause too.

Give us some background - this is an engine that has been placed backed together and this is the first start up?

 

[Jag3350]

Thanks for feedback. Engine hours 750. Compression was low, rebuilt with new bearings and rings. Compression good now. Injectors disassembled, cleaned and reassembled. New glow pugs, glow fine. Voltage to them around 10 volts, rising as a they get hot.
initial thought was low voltage at starter, pulling down to about 9 volts, that’s why I changed the starter. Same result. All connections between bat and starter clean. My thinking is it’s turning a tad slow on start.

I too would suggest looking at glow plugs again - you are not getting the chamber hot enough to burn the diesel to full combustion. Pump alignment sounds as a possible cause too.

Give us some background - this is an engine that has been placed backed together and this is the first start up?

 

[North Idaho Wolfman]

Have you double checked valve lash?
Replace the all the injectors with OEM Kubota injectors, eBay and amazon injectors are junk.
If problem continues then have the injection pump professionally rebuilt.

 

[Jag3350]

I bought the tractor for a song because owner said it started breathing hard out of the crankcase and then got where it wouldn’t start. Was told he needed an engine rebuild. I Cleaned all the old fuel out of it and got it started pretty easily. But it was breathing hard. Then it got where it wouldn’t start, compression check showed 180 on all cylinders. I pulled the head and pan and put a set of rings in it, it started right up. No blowby now and compression 400 on all three. Nothing has been done that should affect pump timing. The only issue now is on the first start after sitting overnight in 75 degree weather it is slow to light off. Doesn’t seem to matter if I heat it 10 seconds or 30 seconds. After about 5 seconds of cranking it starts puffing white smoke(fuel) and starts after about 30 seconds of cranking right into a smooth idle. All starts after as soon as I turn the key.

 

[North Idaho Wolfman]

Did you check the gap on the rings when you installed them?
To tight of rings will make it crank slow.
You said you put O-rings in the Injection pump, did you remove the parts, did you remove the tamper proof screws?

 

[85Hokie]

So, after the rebuild ......... " it started right up "

If it starts fine after a warm up and hard to start cold then I would suspect something aint right in the preheat.......

I am not clear on the first start up that was fine and now hard to start - how many times has it been started since the rebuild?

 

[Jag3350]

Ring gap was checked, was within spec. The pumps were pulled from the injection pump and o-rings changed. I did not pull the plungers in the pumps because I don’t have any specs to measure against.
When I say it started right up after rebuild, I mean it started as expected after bleeding. Then it started fine the rest of the day. 10-15 starts.
Next morning takes 30 seconds to light off first time. After first start of day, immediate start as soon as you hit the key. That’s when I decided to change the starter. New starter, started right up. 10-12 starts that day. Next day back to the 30 sec. first start. Right now if I give it 30 seconds on glow plugs, then start cranking will light off in 20 to 30 seconds, and then start normally until it gets completely cold.

 

[Jag3350]

FYI, I have 3 Kubotas. 2 with the D1105 engine. Both of them the cold start is similar. This one a little worse.
I have a 3350 that starts as soon as you hit the key, hot or cold

 

[SDT]

FYI, I have 3 Kubotas. 2 with the D1105 engine. Both of them the cold start is similar. This one a little worse.
I have a 3350 that starts as soon as you hit the key, hot or cold

Is the cranking speed similar to your relatively new 3350?

If not, inspect/replace battery cables.

That said, I suspect injectors based upon available information.

FWIW: My 2018 B3350 with about 70 hours does not start quickly and never has.

SDT

 

[SDT]

Thanks for feedback. Engine hours 750. Compression was low, rebuilt with new bearings and rings. Compression good now. Injectors disassembled, cleaned and reassembled. New glow pugs, glow fine. Voltage to them around 10 volts, rising as a they get hot.
initial thought was low voltage at starter, pulling down to about 9 volts, that’s why I changed the starter. Same result. All connections between bat and starter clean. My thinking is it’s turning a tad slow on start.

10V at the glow plug bus bar is OK and about all that can be expected.

Cranking speed is crucial. Battery fully charged and battery cables good?

SDT

 

[BruceP]

initial thought was low voltage at starter, pulling down to about 9 volts, that’s why I changed the starter. Same result. All connections between bat and starter clean. My thinking is it’s turning a tad slow on start.

This may be worth looking into. 9v at the starter indicates too much of voltage drop. This results insufficient cranking speed which is imperative for cold starting.

Consider doing some 'voltage drop' measurements. (use clip-leads to make connections so you do not have to hold the wires)
*) Meter leads connected to battery minus -and- starter case.
*) Meter leads connected to battery plus -and- large wire on starter

In both cases, connect to battery POST.... not the clamp.

For each of the above 2 tests, take measurement WHILE CRANKING and expect less than 100mv (0.1v)

Any more than than 100mv indicates poor connection between those two points.

My tractor APPEARED to have perfectly fine ground wire... but failed this test. After cutting the ground wire, I found it was mostly green powder inside the insulation. A new wire really improved cranking speed.

 

[200mph]

2nd the voltage drop test. There are many videos available to demonstrate the technique.