KAD43 running rough?

[A_8]

Hoping for some pointers from our esteemed diesel experts. One of my Kad 43 are running rough which has been getting progressively worse the last few years.
There is no smoke or loss of power, the roughness is not really noticeable at idle, perhaps most noticeable around 2500-2700rpm but still there up to 3900rpm.
Injectors were recently changed and even though the engine run smoother the roughness is still there.
I am now going to let a vp man look at it but want to make sure they don't give me the runaround, hoping to get input on here how to best approach this.
From the discussions I've had most think it's the injector pump. Would you agree and what would the best course of action be to confirm or fix it?

Have them readjust it, have it replaced with a new unit etc. Could it be something else?
The engine has around 1200h and this issue has been "lurking" since maybe 600h.
Not sure it's relevant to this issue but the engine is also running a bit colder than the other, around 5c as measured on the block with an IR temp meter, it stays at 80c up until around 3200-3400rpm.
Thanks.

 

[dragoon]

I would start with getting them to verify that the timing is set up correctly. I understand timing and cylinder temperature can be interrelated, but I'm no expert.

It's possible others have other ideas. Do the engines start the same?

Cheers,
Paul

 

[A_8]

I would start with getting them to verify that the timing is set up correctly. I understand timing and cylinder temperature can be interrelated, but I'm no expert.

It's possible others have other ideas. Do the engines start the same?

Thanks Paul, I have not noticed any issues or odd behaviour starting the engine. Why do you ask, is there some starting behaviour related to injector timing or the pump that I should look for?


Cheers,
Paul

 

[dragoon]

I had one engine too far advanced and one marginally retarded for some time. The advanced engine always started better, with less smoke on startup. But it sounded noisier. I retimed the pump and they behave more similar now.

That said, they both ran smooth at speed and time temperature variation has varied depending on which cooling system needs cleaning.

 

[superheat6k]

I would have the pump removed and sent for re-calibration by a diesel injection specialist.

There is an individual pump element for each cylinder, and these can be adjusted or can wander off tune, and the damage that can occur can be extensive. Also trace quantities of water getting into the pump can cause internal damage and disrupt the proper operation. These pumps can only be set up with the correct calibration equipment.

Then get a VP experienced engineer to reinstall and set the pump timing to the engine.

Poole Diesel; ElectroMec (Reading) are a couple of names I know, but a firm set up to service truck injection gear should be able to do this.

 

[volvopaul]

I would have the pump removed and sent for re-calibration by a diesel injection specialist.

There is an individual pump element for each cylinder, and these can be adjusted or can wander off tune, and the damage that can occur can be extensive. Also trace quantities of water getting into the pump can cause internal damage and disrupt the proper operation. These pumps can only be set up with the correct calibration equipment.

Then get a VP experienced engineer to reinstall and set the pump timing to the engine.

Poole Diesel; ElectroMec (Reading) are a couple of names I know, but a firm set up to service truck injection gear should be able to do this.

Kad43 has rotary Bosch pump , it does not have individual pump elements.
Could be the fulcrum lever fault or low transfer pressure inside the pump which can give erratic injection.