Thermo image on the engine top.

[Rawze]

I have taken a lot of thermography of engines from the top cover like that. Usually, you can see the injectors (all 6) as hot-spots through the cover, but the pics you posted reveal one is quite a bit hotter and is a significant imbalance.

That is an injector doing that. Since you have a 2350, it could also be the electrical coil for it and not the injector mechaincs. it could also be a loose wire connection so check the torque of the screws for the wiring.

You could wait until the engine is cold, take the top cover off, crank it up and watch it warm up with the thermo camera. If it is a coil, you should see it fairly quickly. If something else, it will take longer to spot. Also, you can remove the cover with the engine somewhat hot and should be able to see what it is too.

Before spending $1200+ on a new injector, I would move the injector to cylinder number 1 and perform the same test. Make sure if you do this, you also use Insite to correct the injector trim data too.

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For those who don't know, a good quality thermal camera is a priceless tool for a repair shop.

Here are some examples from the past ...

batteries -- http://rawze.com/forums/showthread.php?t...3#pid11663

turbo and manifold -- http://rawze.com/forums/showthread.php?t...2#pid12452

brakes out of adjustment/ uneven stopping force - http://rawze.com/forums/showthread.php?t...04#pid7804

other problems found ..

http://rawze.com/forums/showthread.php?t...200#pid200
and..
http://rawze.com/forums/showthread.php?t...9#pid33469