i was noticing a small miss in my engine, so i swapped the plugs and wires. it had 8mm packard wire and delco plugs. I put 7mm united wires, and ac delcos gapped to .037 in. the miss is still there, if not worse. any ideas on how to narrow it down to which cylinder is misfiring? im going to change the cap and rotor soon.. but i dont know if thats the problem or not.
also... i called napa, and they said the gapfor the 91 firebirds is .045, but the manufacturers sticker says .035. which one is it?
and what mm of wire is standard in the 91 formulas?

5.7 litre TPI

 

Well the easiest way to locate where your missing assuming its an ignition problem is watch the tach and pull each sparkplug wire on at a time and see which one causes no drop in RPM. From there if the miss is the result of one cylinder you can trace it back plug to wire to cap ect. However there is a possability that the "miss" is not really the result of 1 cylinder not fireing. Also if the manufacture sticker says .037 thats what you should use. I know the older camaros used the 45s but im pretty sure none of the TPI motors did. Any codes being thrown? Try running a vaccum test.

 

.035" vs .045" gap won't make any real difference.
miss only under load, or while idling too?
how did you notice it?
intermittent or always?
put your timing light on each wire at a time, while revving it. If one is intermittent, that's your hole that's missing.

Or read the plugs to find out which one is missing. Cap and rotor are cheap anyway, if you think they're bad, might as well replace.

 

ohm out your injectors.....14-16 ohms is good, 13 or lower is bad...sticking injector could cause a miss or intermittent roughness in the idle.