Well after 86000 trouble free miles, well almost trouble free....
My 06 is now having a hard time starting after you let it sit overnight. It seems that if you try and start it the engine tries to "catch" but then dies. If you just continue to hold the key over it will crank and crank, try to start a couple of times and then start.

I also tried just cycling the key on and off a couple of times before you start it and then it starts fine. It almost seems like maybe the lift pump is going out or bleeding down.

I changed the fuel filter about 5000 miles ago, maybe it's plugging up? No codes pop up and for the rest of the day the truck runs fine.

Where do I start?

 

loosen the banjo bolt on the cp3 and turn the key on if any fuel comes out at all it should have started. the cp3 can run at negative 5 lbs pressure. the ecm will not let the truck start until the rail sees 3,000 lbs. several things can cause this start with the ones that does not cost money re torque the injector tubes, next remove the banjo bolt from the pressure relief valve and place a piece of paper between the valve and banjo and start the truck, no fuel should come out of the valve at any time. next is harder you need to do a leak down test it is easier to do if you purchase the miller special tools but before i bought them i did it out in a field you already did the prv now remove the injector return banjo bolt and collect the return fuel in your wife's measuring bowl over a one minute period this gets messy that is why you do it in the field. let the cp3 return fuel go to the ground i think you will find excessive injector return fuel. with the elimination of the torque on the injector tubes. you probably have a bad injector. to eliminate the bad one you need to block off one injector at a time to find the high flow one. before i bought the cap to do this with i had a #4 injector line that was broke and i brazed the line shut and used it