I have a 1997 Chevy k-1500 5.7. It is blowing a random misfire code and is idleing hard and backfiring. I have replaced Egr, Injector spider, cap rotor, plugs, wires, fuel filter, intake gaskets, upper plenem gaskets and reset timing on motor it self and in the computer. Any one with imput would be great Thanks

 

Have you tested your crankshaft position sensor?

 

I have a 2002 S10 with a 4.3 that had the randon cylinder misfire and after changing a lot of parts I changed out the dist cap again and it fixed the problem. So now after all the trying to trouble shoot of all new parts it will out run any V8.