hello this is a post form a newby. I am happy to have found this site I own a 2000 astro awd. resently I gave it a tuneup but that did not solve my surging problem. at about 45 The van starts to surge mostly on the flat but it has happened on hills. I was thinking it mite be the transmition trying to shift this is only my guess. help with this problem would be very apperciated