so the truck runs and drives just fine, but at an idle it jumps up about 200 rpm every 5-10 secconds. When I pump the top of the fuel filter, no more rough idle. put a brand new filter on thinking it could be that, no changes, pulled the bleeder valve screw and it was totally destroyed so i replaced that and still nothing changed. bought a new water in fuel sensor and it wont fit into the filter so im thinking it may be that. Has anyone had a similar problem or is there anyone who might know whats going on?? i dont think its bad injectors but i just dont understand it seems like air is getting into the fuel lines but not enough to throw a code. this is a completely stock 2001 duramax if that helps you. any help would be appriciated and thank you in advance.