Lets take a look at the aftertreatment fuel block in the ISX

[@vicpetrishak7705]

Is there a test port at this block ? Idle pressure ? Full throttle pressure ? Read on scanner ? Full air to valve or regulated ? Thank You , Diesel Joe !

[@ENGINESHOPJOE]

No test port but you can monitor the valve status and pressure using the data logger found in INSITE. The air pressure is what ever is in the air tanks at the time. The fuel pressure is close to what is in the on engine fuel filter at the time. It has nothing to do with throttle and more with rpm since the gear pump and its internal regulator controls the pressure in that housing IE the fuel in that housing comes from the on engine pressurized fuel filter head.