The fuel injector relay on a 1994 Volvo 850 Turbo is located in the
main relay box, often called the
fuse box, under the hood. It's not individually labeled "Fuel Injector Relay" but rather is usually identified by a number or symbol in the relay box diagram located on the inside of the cover. You'll need to consult your owner's manual or a Volvo 850 repair manual to find the correct relay based on its location and numbering within the fuse box diagram.
It's important to note that the exact position can vary slightly depending on specific options and regional variations, so referencing your owner's manual is crucial.