i have a 2000 dodge and all at once the engine started knockin really hard, the injection pump is junk, i didnt know if with the injection pump bad if it would cause the injectors to fail and make this kind of knockin noise. it is a vary loud thud noise. could this be an injector not working properly?

 

crack each injector line one by one and see if one of theym doesnt make a difference in the way the engine idles. the one that doesnt change anything is a dead cylinder.

 

yea try that could be a valve seat problem also