My truck stalls after one minute of idle, but only the first time I start it. When it's cold outside, it cranks a little for starting and makes a big white cloud. It makes a knocking sound when I run it cold on low rpm.

I just changed all injectors because I had water in fuel. I discovered the problem after having change it all, I had to replace 3 other ones again so I knew that was the problem. So water went in the other 5 new but did not break it, maybe until now? The injector balance were inside the spec when engine was hot.

I thought it was fuel pump that was not delivering enough fuel volume on start but I have no other symptoms related to fuel pump.

Can I drive it like that until something break? I have no engine light or Trouble code and when I run it hit everything's good.

GMC Sierra 3500 2009 SLE duramax lmm

 

I would suspect a stuck or leaking injector that clears up when warm. This will be hard on the pistons and cylider walls. Try pulling the glow plugs and disabling the injectors. Crank the engine over and see if you get fuel comming out of any glow plug holes, that will be the bad injector.

 

My 07 LMM just started doing the same thing; stalls after less than one minute of idle, but only the first time I start it in the morning. Check engine light comes on but when I run the codes there are none. I clear it anyway, the check engine light goes out and I crank it again. It cranks over quite a bit before firing but once it starts everything seems fine. Later in the day when I start the truck it cranks over a bit more than usual but starts and runs fine.

Any ideas?
Thanks

 

sounds like an air leak at the filter/housing. try priming it prior to starting and see if it helps. also you can change out the rubber hose coming out of the filter with a clear one and watch for air bubbles. there should be none. if you have air then you may need to rebuild the filter housing. you can find DIY kits for cheap.