I just been out to my car when I switched the ignition on the Engine Management Light(EML) came on, I started the engine which promptly shut down after about 7 Seconds; the vacuum operated throttle was being forced to the closed position. I disconnected the vacuum pipe from the valve to keep the engine running and after a short while the EML went out and I was able to reconnect the vacuum pipe. I drove for a about 3.5 miles and the EML can on again but went off within a few seconds. I've had a U581 code reader on it but no fault codes are stored. Do any of you VX Gurus have any suggestions as to what the problem might be? I've already had the EGR valve and MAF sensor replaced.