Engine miss firing

[AlpineRaven]

Info/Story: VN Commodore S 1991, recent engine conversion from series 1 to series 2, full wire loom & inlet & exhaust manifold swap, converted engine to series 2.

Today was driving around, engine was running nicely for about 2 hours (driving around town) before I drove really hard uphill and now the engine is miss-firing, idling okay but can hear one miss fire, sounds like one spark plugs isn't working.

I replaced ECM to other one from Series 1 commodore, no change. Changed spark plugs to new ones - no change.. Since darkness fall in, I am bummed what else it could be?

My thought would be tension leads that could be on way out but how could it go after driving hard?

Any second thoughts?

Cheers
AP

edit: engine still missfires any speeds - from 0 to 80kmh, didnt drive over 80kmh.

[beefcream]

check coilpack... every trouble ive had with missin has been due to my shite coil pack

[1991_Vn2nV]

I would say ignition leads or coil pack.

[AlpineRaven]

check coilpack... every trouble ive had with missin has been due to my shite coil pack

Can i use series 1 coil pack?

Is there any types that are good ones?

Is it common for them to cause miss-firing?
Cheers
AP

[druthless]

yep you can use series 1