Hello,
I have a 2004 A4 Cabriolet and having misfire issue on cylinders 2,4 and 6 all in the same bank. I have replaced fuel pump, fuel filter, plugs and coil pack. Car will have misfires and sometimes dies and would only start if I shoot starting fluid into intake. I am trying to located the fuel pressure regulator which is not on the fuel rail. Can anyone please share with me where I can locate. also any ideas what else I can look at to try and solve this.

Any help would be greatly appreciated

 

Although you did not find the fuel pressure regulator on the fuel ramp, it may be installed separately. It can be found on the fuel line that runs from the tank to the engine. Check your car's manual or contact your car dealer to find the exact location of the regulator.