Truck Repair: CAT3406B, definetly, lifter

Question
had a miss was no.1 replaced injector still missing after several times trying to time it noticed the lifter not following cam downward have push it down is this common or does it need replacing also if so how

Answer
Is That the rocker for #1 that you replaced? Thats definetly not right the injector spring should keep that rocker in contact with the cam at all times. Would turn it around to where its not in contact with the cam and see if the injector spring has come up to the top of its stroke there has to be something binding up. Weather the injector is coming back up to keep it in contact with the spring or the raocker is sticking on the shaft. But with the missing and the rocker not in contact with the cam i would have to say there is a spring broken in the injector.