Sorry it does when its around 4500 rpm and of course hot because I would not give it a kick when its cold. I believe the engines won't stand this. Some guy told me that I should try with octane booster. Well it helped a bit, but not much. But I am running Shell V-power, and I think its beginning to run a little longer per litre. But I don't think the to kinds of jumping are related. I wonder if the "cold jumping" is from the rear diff. Does anyone have experiences with this?