I seem to have developed an engine knock in the #5 cylinder. It happens at all speeds. I have eliminated the crank and rods by useing a stethescope. If I place the scope on the #5 injector fitting I hear a ping on each power stroke. I have eliminated air in the fuel system, fuel qaulity, and engine overload as stated in the factory book. The only options left are incorrect injection pump timing and injector malfunction. I installed a reman vp44 last summer and the truck throws no codes(thank god no po216). I guess I am looking at pop testing the #5 nozzel? Any suggestions?

 

I had a locked-up injector (likely due to sloppy installation by me) cause a nasty fuel knock... with the stock injectors back in the truck, the knock was gone even though the truck ran like crap because of a melted piston.

 

I doubt if I have a melted pistion but the knock is definatly there. I am thinking of my repair options, of course I would love to get some mach 1.6's but with my tranny getting up there in miles I don't think I want to chance it right now. I guess I will call the cummins house and see what the money will look like. Any tips or tricks to share?

 

Pull the injectors yourself and take them to a fuel injection shop for testing... I'm at the same miles you are (well, I was...) and even though I upgraded to the 1.6s just for the fun of it, I found out after the fact that my stock injectors weren't in good shape. Three of them were dribbling and all of them were popping-off around 230 bar (stock injectors should be 305 bar when new).

I've seen sets of stock injectors on ebay for fair, even cheap prices... I'll have the stock set from my replacement engine available, but probably not soon enough to help your situation.