Caps used to block off the fuel rail during fuel pressure diagnostics in 2003-2022 Cummins, 2001-2022 Duramax, and 2008-2022 Ford engines.
Helps in identification of faulty diesel fuel injectors and used to diagnose engine knock sounds.
Install the cap on the fuel rail in the place of the injection line.
When the cylinder with the failed injector is capped, the rail pressure will rise and the vehicle will start.
Set comes with five different caps in a vinyl holder.