I have a 92 s-10 blazer with the vortec. Recently it started acting up on me. It wants to cut off, comes close, but never does. It also consumed a tremendous amount of gas until i replaced my map sensor. I got my fuel economy back which is a pluse, but it still "studders" even when I am idling. One more thing, evrytime it starts to die my exhuast had a "bubble" or "missing" sound to it. Its real annoying sitting at red lights and haveing people stare at me when my engine almost dies it surges so it looks like im trying to race them. Please any suggestions?