Im just wondering what do I use to cap off the fuel line to test my injectors?

 

The Cummins part # is 3164325. Just asking, do you have the abilty to raise the rail pressure above 20,000psi @ idle ?

 

you can cap the line and do a flow test without having to raise any pressure and see if the injector is allowing the pressure to bleed off

 

According to Cummins tech info, rail pressure should be raised, as leak may not be detected. With rail pressure raised, max return on all 6 cylinders is 300ml per min or 10.1 fl oz. I guess if you have one that is leaking really bad, you likely will find it. Hope you find it.