Audi 2.8 - 1998. All six injectors register open circuit. I checked the relay, fuel pump operational. Measured voltage on injectors 0, when measuring between battery earth and injector positive - 5 Volt. Checked continuity between injectors and ECU box (earth), no problem.
not an audi expert, but I would check all the wiring that you possibly can. there could be a short somewhere in the wiring or a bad connection.
Search Audi A6 Questions
Audi A6 Experts