[Christ]

Adding ANYTHING to that off-road fuel will not negate the red-dye test. They don't test it for the color, they test it for the chemical makeup of the red dye. If they find it in high enough concentration to assume you're using off-road fuel, you'll be responsible for a hefty fine.

That said, I use red fuel in my truck a lot, because I just don't really care. I also use UMO/WMO after a 5 micron sock filter, and ran the same in the diesel.

Don't let the engine keep turning if it's not getting fuel, this can damage your injection pump. The fuel lubricates the injection pump, so "running dry" can/will wear it out.

Adding a inline pump alters the fuel injection timing slightly on some types of diesel engines, notably those with Bosch pumps. They depend on internal pressure to time the injection event. The external pump won't change it much, but can change it.

The problem with my Golf starving for fuel was a pinhole in the pickup tube where the rubber hose connected. Sliding the hose and clamping it over the pinhole fixed the issue.

The PO thought it was the pump "losing prime" which is indicative of a worn front seal. The seal costs about $3, and can be changed inside of an hour. Make sure you're aware of how to re-time the pump (same as replacing the timing belt).