Have a 95 blazer with 4.3 missing on the #4 cylinder. Have checked the distributor timing, replaced the distributor because the top of the shaft spun. Installed new plugs, new cap, new rotor, new spider injector, new fuel pump, new map sensor, new IAC motor, new EGR....The #4 cylinder is wet on the plug. The wire is good and have watched the spark on another sparkplug and it appears bright. The "SES" light flashes constantly. It will work through the miss, but only at a higher RMP under load. Usually takes 10-15 seconds to clear out, but once it does it's fine. Any suggestions???

 

Did you gap the spark plug correctly? Was there and chance you bumped the lead when you installed the plug? also check to make sure none of your wires are touching one another, or they could crossfire, or do funcky things.