Have a 1990 300ZX. Engine cuts out when at steady speed -- just like turning the key off. Any speed, any temperature. Need to back off throttle and then reapply throttle to keep running. Intermittent. Does not cut out under acceleration, ever. Recent fuel and air filters. Reseated two big connectors front of engine right side (from drivers seat). Biggest connector has green male and female contacts. Burnished male connectors -- cannot get to female connectors.