ok. to start off. i have a 96 z28 camaro. i have recently changed the opti, plugs, plug wires, and changed the injectors( which all were used)..when i bought the car i was told it had to bad fuel injectors. i knew some guy who was selling a set of them so i bought them and changed all injectors. turns out the injectors werent the problem. about a thousand bucks later it came down to the distributor. changed it and the car ran great..for about a day. then i start to have misfires with cylinder 3(which had several, more dead than alive) and number 6 that wasnt to bad. the car had all new spark plugs so i didnt think it was them. so i changed all the plug wires...and still no change. so i pulled number 3 plug out. cleaned it up a bit and it ran a little better. so i went and bought 2 brand new plugs thinking this is the problem. changed them and had no misses. car ran great..only for about 2 days this time. car still runs alright but start to miss a little. is my next step those injectors again?

 

first swap out the 2 plug wires in question with 2 that are good. If that doesn't help swap injectors the same way. I feel you have side firing plug wires so look for spots on the wires near where they turn a corner or are pinched between things.

 

if you have plug wires arcing, you can usually spray water from a spray bottle on the wires and make it misfire really bad. if that doesnt change anything, check your plug again-is the ceramic cracked? is the tip burned away? is it badly fouled? i wouldnt think injectors because when you cleaned the plug or replaced it, the engine ran ok for a while. i agree on swapping plugs and wires with a cylinder that isnt missing and see if the misfire moves, then you know what it is.

 

Try starting the engine in a very dark place and you will see if there is voltage "leaking" You will see where the problem lies. Some arcking will appear even at the spark plugs noticed as a dull glow this is normal. A mechanics mirror with a telescoping handle will aid in this . Ted