If I turn the car on when cold it idles fine and revs fine (although it is harder to start up now). However if i take it for a drive 100m down the road it starts mising and smoking and smelling like petrol. Took plugs out and no.5 was wet so its not firing and blowing the smoke and fuel out exhaust. It has brand new spark plugs and wondering if coil packs would make it do this?

o2 sensor or afm buddy.

Not coils or anything? Strange how only one spark plug is wet

Try gaping the plugs down to 0.8mm as the boost can blow spark out.. In the dark start it up and see if the coil pack is sparking to the rocker covers or any metal common problem with stock coils, most try wrapping them with a heap of elec tap to get out of trouble.. Try swapping the coil packs around and see if the problem moves..

Car idled and revd fine until I took it for a 50m drive and it started misfiring, smoking and smelling like fuel. Replaced spark plugs and coils and now it barely starts, runs extremely rich (??) and fuel just pours out the exhaust along with a mist. Dafuq is wrong with my piece of **** holden

Have you checked the simple stuff like vac leak (cooler hose blew off) when boosted up road, air flow meters are notorious for failing also .

I didnt boost up the road, i havent taken it above 3k rpm since engine was put in. im gonna unplug afm tomorrow and see if it runs alright up to about 2500rpm. If it runs alright with afm unplugged il get a new afm

Are they old plugs? As in are the the plugs that where in it when you swapped it in from the front cut? Try new plugs, or swap one of the other plugs into that cylinder, pull your injector clips and turn it over looking for spark.

Brand new plugs and coils. Gonna try unplugging afm tomoro

Found the problem. Turns out some injector wires had been rubbing up against the block or something and it had kept like 3 of them constantly earthed which means they were constantly wide open. Explains the overfueling haha...