I have a 97 626 with the 2.5 engine. The valves that open the butterflies for the VRIS, won't open. I put a vacuum pump on the accuators and they are ok. The engine has a dead spot at 2000rpm to about 3000rpm. it idles good no misfires, and runs good after 3000rpm or 45 mph. doesn't matter if in park or drive acts the same. Do you think I'm looking in the right place? or maybe MAS? but the VRIS isn't working right for sure.