This is a 1992 4.3 vortec and I just got the thing. It's in a Bravada which is totally irrelevant but while warming it up for the first time the dash which is fully electronic display suddenly got brighter and the engine revved up for about five seconds and then went back to normal. While driving it I stopped along the road and while sitting idling in gear the thing did it again. This is a kill someone problem and I hope someone has the solution. It's a little scary.