Over fuelling cossie
 

Had my car motd recently and was told it was over fuelling on no 3 cylinder, and they thought it was the injector. Put that injector into no 1 cylinder still no 3 is not firing. So it's not the injector. Plenty of spark, plenty fuel (probably to much) I have changed the plugs, but still no go. I have run out ideas. Any thoughts please

Fuel pressure regulator diaphragm has split / perished . Check the vac pipe isn't leaking fuel

Thanks didn't even think of that.