I have a 1990 2.6 auto 190e. The engine starts and runs but cuts out and stops intermittant, but now more and more. The fault seems to be 12v supply to the idle control valve which comes and goes. I have tried to find source of supply ,i:e ignition, switched fuse, relay, followed cables all over but no joy. Can anyone help with this problem and the motor is running extremely rich, is this connected to idle valve fault