Cummins QSX15 Smoking

Get out the ever so handy infra red thermometer and shoot each exhaust manifold runner within a inch from the head under the loaded smokey condition. Seconds later you will know what holes have issues. Do the same at cold start and watch them come up. The #1 hole will usually be cooler because of the water pump on the front. 30-50 degrees in differences will tell you where a problem is.

As stated earlier in the post I have done all the injector checks that Insite will allow. ( I think Insite should be renamed In sh**e)
There are no duration figures, just on and off.
I have checked through them with a small load on the engine and have replaced the weakest.
I like your thinking Doylex, only problem is the only way we can load this engine is to put it in a crop travelling at around 8kmh.
Add that to the fact that there is nowhere to stand near the engine, on more thinking I guess I could remove top panels and stand on top of the engine I guess.
I will try that.

Do you notice the smoke when the engine is cold or after it reaches operating temperature?

Hi there, when engine is at operating temp

Is the piping from your air filter to the turbo made of hard plastic or flexible rubber ?

It's either hard plastic or steel

Ok. If you have any rubber in that intake system check that the spring has not collapsed. What will happen is as the engine reaches operating temp. It will soften the rubber and under high load/high vacuum the rubber will cave in causing an intake restriction. It isnt easy to spot because you have to be be around the area when the engine is loaded to see this phenomenon or alternatively you could remove you piping from the turbo inlet. Black some is unburnt fuel and from your previous posts it sounds like you have done everything fuel system related with an exception of the injectors. As far as faulty injectors, from what you have described, not being down on power & cutout tests being ok I would say they are ok. I would be looking at an illusive intake restriction. Just my 2 cents.

Thanks for the input, I replaced all the rubber lines in the intake system last year when I fitted the new intercooler.
Iam going to contact cummins to see if there are any software updates for the engine.

trackdoc, Can you post the engine serial number? I will see what I can turn up through Quickserve.

I am at a mine camp at the minute, will be 2 weeks before I get back home.
I can post the serial number then.
Thanks