Furniss
Well-known member
It looks like the injector your finger is pointing at, I`m not super familiar with the merc system but there should be a filter in the system, and maybe an air/water separator filter, often get overlooked at service.
As @V8Druid says someone to plug in would be worth it, to point you in the right direction (provided they know their onions), usually any failure, sensor, wiring, out of parameters stops them working.
Will have a look cheersIs there a Facebook group for merc trucks, sometimes they can be a goldmine for common fault fixes etc