D722 starting

[Stubby54]

Guys. Im from UK and I have a Jacobsen triple with a 3 cyl d722. Had a cracked cylinder head and no compression. I have cleaned pistons and replaced rings. Fitted a good head. Had pump and injectors tested and reconditioned. Heater plugs working. New starter motor. Good diesel supply. Good compression.
Will not start but emmits a helluva lot of smoke and exhaust gets warm.
Will not fire on ether, and actually stalls the starter.
Any ideas please? I thought pump timing might be out but Im nearly out of my depth.....

 

[BruceP]

WHOA - Never EVER use starting-fluid (ether) on a Kubota engine. This is a great way to crack piston or head... even con-rods have been known to bend like plastic.

With that said - it sounds to me as if the injection-timing is incorrect or the injector-pump internals were not reassembled properly.

 

[Stubby54]

WHOA - Never EVER use starting-fluid (ether) on a Kubota engine. This is a great way to crack piston or head.

With that said - it sounds to me as if the injection-timing is incorrect or the injector-pump internals were not reassembled properly.

 

[Stubby54]

Thanks. Sorry Im more of a Cummins / Perkins / Iveco size person. Never nornally use starting fluid but did just give it a quick try. She just stalled and made no attempt to fire.
I did have running but it was cranking for to long and sliw to come to life.
Think I will attempt an injection timing check next.
Thanks for the advice.

 

[North Idaho Wolfman]

Thanks. Sorry Im more of a Cummins / Perkins / Iveco size person. Never nornally use starting fluid but did just give it a quick try. She just stalled and made no attempt to fire.
I did have running but it was cranking for to long and sliw to come to life.
Think I will attempt an injection timing check next.
Thanks for the advice.

Are you preheating the glow plugs before cranking?
Are the glow plugs being heated during cranking?
Did you bleed all the injector lines to the top of the injectors?

Have you removed the injection pump?
If you did did all the shims under the pump get put back in?
If they did then the timing is right.

 

[Stubby54]

Are you preheating the glow plugs before cranking?
Are the glow plugs being heated during cranking?
Did you bleed all the injector lines to the top of the injectors?

Have you removed the injection pump?
If you did did all the shims under the pump get put back in?
If they did then the timing is right.

Are you preheating the glow plugs before cranking?
Are the glow plugs being heated during cranking?
Did you bleed all the injector lines to the top of the injectors?

Have you removed the injection pump?
If you did did all the shims under the pump get put back in?
If they did then the timing is right.

 

[North Idaho Wolfman]

You hit reply twice, but didn't type anything?

 

[Stubby54]

Yes Im heating correctly. No they dont heat when cranking. Iv tried heating two or three times befire cranking. I have also tried wiring direct so they are hot whilst cranking.
Its purged at pump and Iv removed air from injector nuts.
I removed pump and replaced it after it was reconditioned.
It has one shim under pump.
Certainly sounded over advanced to me... I should not have used starter fluid but when I did it was slowing the starter like a petrol with to much advance.
When it did run (and I dont know why it wont run now), it started badly with long cranking and lots of smoke.
Has anyone had pump timing thats moved or worn?
Im not sure if someone else has been tampering with it before me.
How many shims do you usually find under a pump?

 

[Stubby54]

You hit reply twice, but didn't type anything?

Whoops sorry first time here!

 

[North Idaho Wolfman]

Yes Im heating correctly. No they dont heat when cranking. Iv tried heating two or three times befire cranking. I have also tried wiring direct so they are hot whilst cranking.
Its purged at pump and Iv removed air from injector nuts.
I removed pump and replaced it after it was reconditioned.
It has one shim under pump.
Certainly sounded over advanced to me... I should not have used starter fluid but when I did it was slowing the starter like a petrol with to much advance.
When it did run (and I dont know why it wont run now), it started badly with long cranking and lots of smoke.
Has anyone had pump timing thats moved or worn?
Im not sure if someone else has been tampering with it before me.
How many shims do you usually find under a pump?

It will sound over advanced when using ether as it fires off way t early and bends/ breaks parts.

Timing doesn't "move or wear on these engines.

The glow plugs should have 2 circuits that feed them, a preheat circuit and a crank circuit.
A newly re-ringed engine that gets to hot too fast is almost always a result of rings that are too tight.
Have you done a compression test?
Have you tested each of the glow plugs?
Have you pulled the injectors or glow plugs and seen if you can freely spin the engine?

Too much fuel, EG bad injectors, will cause too much smoke on cranking.
Was it a professional shop that did the rebuild on the injection pump and injectors?
Or was it a local bloke that said I can do that?
a Normal mechanics shop will not normally have the equipment to properly test and rebuild those parts.

 

[Stubby54]

Thankyou. Compression is 385psi nearly equal on all 3.
Pump was sent to a recognised Kubota service agent, and injectors are new.
Each (new) glow plug is glowing correctly.
I did check ring gaps before fitting to pistons.
My glow plug light does not light up when cranking. I will look at this.
Engine turns ok..I turned it to set valve clearances.
I know it sounds crazy but I must be missing something.
I will repair heater plug cranking circuit tomorrow and try again.

 

[Pau7220]

Compression is 385psi nearly equal on all 3

Have you checked the compression after the starting fluid (ether) use? It only takes a split second to bend a connecting rod or break a piston. Especially knowing it locked up when cranking. Compression spec is 413-469 psi if this sheet is correct.

https://enginetechspecs.com/kubota_d722_specs.html

 

[BruceP]

It only takes a split second to bend a connecting rod or break a piston. Especially knowing it locked up when cranking.

Will not fire on ether, and actually stalls the starter.

This is NOT a good thing!!! Knowing that use of starting-fluid can damage Kubota engine AND knowing you experienced stalling of starter.

I did have running but it was cranking for to long and sliw to come to life.

This sounds like GlowPlugs are not heating up. Use voltmeter to validate ~10v on the jumper between the GPs. (clip meter-minus lead on battery-minus post)

QUESTION: Has it EVER run since using starter-spray?
If not... the engine may have internal damage.

 

[Stubby54]

I will recheck compressions again. Wishing I hadnt tried easy start.... thanks guys I will report back.
PS glow plugs are new, tested and working but not working during cranking.

 

[GreensvilleJay]

It may be designed to NOT power the glow plugs while cranking. The WSM should tell 'how-it-works'.
I can see the 'sequence' being ..heat GPs for 30 seconds then power to the starter. That allows ALL the battery energy to spin the starter faster than if GPs were also powered.
GPS take a LOT of amps.
Pretty sure my BX23S doesn't power GPs at same time as starting. Now, I'm curious and I'll have to go look...

 

[lmichael]

Yeah the plugs take a good amount of juice and when you flip over to "start" position all other electrical draws are cut off to allow all power to the starter. Especially since my understanding is diesels need a certain RPM to start or never will. But my D782 is the same on my G2160. Turn to start position and plugs shut off

 

[Stubby54]

It may be designed to NOT power the glow plugs while cranking. The WSM should tell 'how-it-works'.
I can see the 'sequence' being ..heat GPs for 30 seconds then power to the starter. That allows ALL the battery energy to spin the starter faster than if GPs were also powered.
GPS take a LOT of amps.
Pretty sure my BX23S doesn't power GPs at same time as starting. Now, I'm curious and I'll have to go look...

Checked mine and the green light goes off after a few seconds but when cranking theres power to the GPs.
Damn thing is nearly starting! The manifolds getting hot but it just wont pick up and go.

 

[GreensvilleJay]

can you put a second battery in parallel ? I've done that with my forklift to get her to spin proper speed.
GPs would drain one battery low enough, it wouldn't spin the engine over to fire could enough.

also , maybe blow compressed air into the exhaust to remove the buildup of unburnt diesel fuel ? kinda like a 'flooded' gas engine

i know once the forklift starts92.5 then 3 then finally all 4..) it spits out all sorts of 'stuff' until all 4 cylinders run right !

 

[North Idaho Wolfman]

Check your compression then we'll go from there.
If the compression is bad, tear down is next.
If the compression is good, then since it ran once, it's probably got air trapped in the fuel system.

 

[Stubby54]

Check your compression then we'll go from there.
If the compression is bad, tear down is next.
If the compression is good, then since it ran once, it's probably got air trapped in the fuel system.

Well just rechecked compression and iv lost most of it on cylinders one and two. Its coming to pieces again. I wont be using ether again. Its now come to light that someone has removed the pistons due to rings being stuck in the grooves, cleaned them out and fitted new rings. I must admit when it did start it cranked for ages and did breath a fair bit.
So I will do the job properly.
Thanks for the advice guys.