I have had problems with knocking and some raw fuel smelling smoke rolling out my exhaust.
Well I pulled them out today they dont look to bad they are going to need o rings of course none of the o rings were broke but a few are a lil chewed (the bottom o ring closest to the nozzle) ... I also noticed when I pulled the I believe on the number 7 cylinder where the knock was coming from the bottom of the injector looked like it was stuck open where all the others were closed so I sat it to the side but when I looked at a few minutes later it closed up so I am thinkin it was the one dumping all the fuel.
you need to get a buzz and contribution test done with a scanner. you can check the injecors while there out. go to diy-injectors.com and and go to the FAQ page and you can find a way to check you poppet, solenoid, and armature.
I just switched out injectors from AB to AD and the truck starts right up and idles fine but it is dead it feels like something is holding it back there is no smoke or noises the temp and oil pressure are good but the exhaust temp feels a little warmer than usual.
Could it be the HPOP or fuel pump I dont know I boggled I read that the AD's should do fine and I have heard u need to change a few things.