I have to ask, even though I know you may have checked,
have you checked the basics like firing order carefully
can you post clear pictures of the spark plugs with each cylinder # listed?
have you checked for vacuum leaks?
drop to the basics and work up, youll find the problem,
a great deal of the cars I see, and work on,
(remember most are now 20-60 years old)
have basic mechanical or sensor or electrical connection issues,
so I've generally found that checking the basics,
like replacing plugs, checking compression, checking oil pressure, and fuel pressure,
checking for a worn cam, before starting to check the,electronics, and if possible
pulling the trouble codes and doing a basic ignition, and fuel system check can produce amazing results,
I've had guys tell me they just need a tune-up... then we find a completely worn out cam lobe,
a busted push rod, a rocker loose,
or a couple spark plugs completely oil fouled,
or 6 cylinder holding 150 psi and two at 90 psi on a compression test
or a couple injectors not even firing