Where is Fuel pressure injector located on a 1990 Mercedes 300E?
Attached to the fuel lines that come off the fuel distributor. Follow the lines towards the head.
Hope this helps.
If it is just one injector, it is a bad injector or a problem in the wiring harness or connector for that injector. If it is all of the injectors, it could be a fuse, the entire injector harness, a broken loose or unplugged connector on the injector harness, or the fuel pump or fuel pressure regulator.