Possibly a faulty wiring join, or an ECU circuit board problem? If not fixable yourself, Injectronics repair faulty ECU's

Gday all   My XG starts and runs well cold, then as it warms, it develops a miss.   By unplugging injectors to test, it seems to be missing on 2, 4, and 6. This corresponds with Bank 2 injectors    Any ideas of how to test?   To me it sounds like I need a replacement ECU.

Facebook sux,compression calculator just as bad....   Latest & greatest from Andy across the ditch, drum roll please 🥢    650hp 408 Cleveland build, yes you heard that correct or should I say read correct.    Facts gathered to date Aeroflow 4.000" block immediately available or 4.125" block wait until December.   Bore 4030 H beam rods 6.000.   Screw all that just straight to the nitty gritty,  Compression target perhaps 10.5.1 to 11.1 prepared to use 98/100 octane.  Heads are going to be CHI 225 ither 60cc or 67cc planed down to 65cc. Some suggestions point towards 65cc would give me 11.1 Compression using a -13cc dish piston & zero deck.  Ultimate goal being 650hp.  Some other trivial factor inners, CHI 7.2 single plane intake, forged Scat stroker kit ,242/250 solid roller cam...   10 million $ question is correct negative CC Dish piston?   What sayeth thee...   Forgive all the dribble it's been an exhausting off & on 3 days. Really just trying to seek a simple answer to a complicated equation 

I have been considering that a reco box is what might be needed already some time ago...I found the below thread, which gave me the incentive to just pull it out and see if it is simply able to be adjusted or needs repairing if even at all possible, as I assume some boxes are too far gone in some way. I have never had any experience with disassembly and repair of these before.    This thread below, also made me consider having a go at doing it myself, but one thing in  particular that I will pay for, is getting diff's done when changing ratios. I have been looking for  places to get a reco steering box from and only one didn't require a changeover box... Just weighing up the options, like, I have no idea what to look for as far as what parts are good or not, if I have ago myself... or If I pay up for a good as new reco one, then at least I have warranty if there is a problem... And I no offer myself warranty on this undertaking...🤫 Jury is out as to which way I will go, but have several other priorities also!        

Seal kit and DIY, is what I'd do... Even purchasing tools, would likely end up cheaper

there's certain underdash units they used to refer to as KNEE FREEZE air con, because the vents just pointed straight at knees. i was going to fit one to My transit van (1980 model i sold ages ago now) but make a front panel with ducting up higher. 

so something to think about when looking for one, is if you can get outlets to point where you want it to.    also, don't be tempted to use say an XF air con pump that likely bolts on,  there's a Sanden unit that's much much more reliable that would be the go if possible.  @SPArKy_Dave might have some ideas for air con if you are lucky. 

Total valid points, the more I drive the car about, the idea of just putting sniper injection on the log motor as is and just cruise around seems like a good idea.   I probably should just start by getting a reco'd strommy and electric dizzy and fit it and see how it goes as is.   It's spent the last couple of weeks as a daily and it's been very pleasant to drive around, gotta get rid of a few rattles and squeeks but other than that and being a little cranky when cold it's just such a nice car to drive about.   Gotta get aircon for it now summers around the corner...a retro under dash unit would be right a home I think.        

give your 250 hater mates a shifter and say you've got 5 minutes to replace the starter motor.. (it's that easy) alternator is probably 5 minutes on a non air con XD 250... they got harder with air con fitted though.    try those jobs on an XG and you'll hate your life choices lol.    don't bother proving other people wrong, with large sums of money almost anything is possible..  just build your engine to behave how you want to drive it. you'll be hating the 13s choice if you think it's too noisy, uses too much fuel , can't cruise on 100kmh for hours etc if you only get to a drag strip once or twice ever. 

https://youtu.be/gSzkrWlIQv0?si=NkodMEgnPMw_doZl   I hate that I know this car exists and it's totally possible for a NA crossflow to run 10's...it validates my dream of breaking in to 13's with a 250....just need to know the formula for to prove my 250 hating mates wrong...

@SPArKy_Dave Tassie based, be expensive to post to mainland for changeover surely? or do Repco do them.