Grey smoke on startup

[tsywyk]

I bought a 2011 LML from a family member and am trying to solve an issue of smoking when it is started, when its above 10degrees C out it smokes only for about 5 seconds and goes away completely it also has a rough idle during that period and clears out when the smoke does. In the cold it can last for up to 10 minutes of idling and then a minute or so of driving then clears up drives fine. i have noticed at idle when it is warm out (not sure about cold) that there is 1 cylinder that feels like it almost misses ? its like a slight vibration or rather the while firing order isn't smooth if that makes sense. I have replaced the Glow plug module and all the glow plugs, no following engine lights now no other codes either, fuel filter is fresh and i was told the truck has done this since he got it 3 or 4 years ago. He bought the truck fully deleted. i am aware it is likely an injector but i don't want to replace all of the injectors to solve the issue.. so how do i identify the correct injector? i pulled the glow plugs after it sat for a week and all of them where bone dry. Is the 9th injector possibly just turned off in the tune and now leaking ? would that cause a rough idle though? how else can i injectors? what else could cause it ?

 

[2004LB7]

With a bidirectional scan too, you can shut off one injector at a time to see if it clears up or reduces. That should help narrow it down

 

[tsywyk]

With a bidirectional scan too, you can shut off one injector at a time to see if it clears up or reduces. That should help narrow it down

I was reading about that in another form but I only have about 5 seconds to test on each cylinder and then I have to wait until it's cold again so that's just a big waiting game I take it ?

 

[2004LB7]

I was reading about that in another form but I only have about 5 seconds to test on each cylinder and then I have to wait until it's cold again so that's just a big waiting game I take it ?

Yep. Or just live with it as you are living with a deleted truck and that is just going to be something you get. If it had the DPF you'd likely never even know if it did it

If it's only doing it when cold. Maybe it's tune related with either fuel pressure or timing

 

[TheBac]

Maybe record data with main rate and each injector listed and see if anything changes drastically once the engine warms up?

 

[tsywyk]

With a bidirectional scan too, you can shut off one injector at a time to see if it clears up or reduces. That should help narrow it down

Ok. So I finally got scanner from buddy to do the injector on off and when I do it I only have about 5 seconds before it clears up and the lope stops. What exactly should I be doing and watching for ? I turn it off and the smoke should reduce or go away? I can't turn the injector off before starting the truck as far as I can see unless I'm just dumb so am I doing correctly ?