98 blazer p0300

hi new here i have a 98 blazer code p0300 is all i am getting. last year when i bought it i changed plugs with acdelco platinum, new cap, rotor, wires. had no probs last week my wife took son to school came home. i got in it 5 mins later started spitting sputtering and get code p0300 checked cap seemed fine fuel pressure seemed fine new i.c.m. cam sensor, t.p.s . took plenum off and looked at the cpi no leaks i cleaned it all up carbon buildup still it runs like crap . o yeah the plugs loook good as new checked them no sparks on wires checkedcan smell gas tho. i can fix mostly any car but this one has me beat im taking ideas to go from smooth one minute to spitting and sputtering the next o yeah new gas 2 new filter thanx

code info for P0300 is
Random/Multiple Cylinder Misfire Detected
im not sure if you said you had spark or no spark and on which cylinder. did you double check your wires on the cap for the right placement, as dum as it sounds, something you KNOW you cant get wrong, sometimes slips by you, as it happened to me.

ok guys i fixed it after i put 300 dollars in it and was ready to send it to the shop i decided at last attemp to change the rotor button cuz was only thing not changed did the trick some how that damn thing was bad a word of advice to all change rotor and cap first NO MATTER WHAT THEY LOOK LIKE OR HOW NEW . the parts looked new and was only 6 months old thanx 4 all the help i didnt get but i will try to help all

As you have already found out, the aftermarket rotors for the 4.3l with the flat distributor cap are junk. I chased my tail for a whole day only to find out that the aftermarket rotor I installed just one month earlier was the culprit. I put an ac/delco unit on and had no issues for the next 40,000 miles and then I sold the vehicle.