Help, I have a fiat multipla JTD on my driveway with 64000 miles on the clock, and it has a problem. Often, when I start it up, the engine will not respond to the throttle, or responds very slowly, until there is a sudden surge of power. Also, if its been on for a short time ~3 minutes it will do this at the traffic lights when coming out of idleing. Any suggestions - could this be a problem with the egr valve?