groomers

Hi guy having a few issues with the saph, started off with complete loss of power over 7 psi boost, had new phase sensor and cps fitted (gapped) and plugs hard wired on bulkhead, all plus on engine were contact cleaned and earths cleaned up.
Misfire then got better would get to 10psi also noticed exhaust manifold and downpipe glowing red after nursing it home off boost stuck it back in the garage in a strop!
Now fitted a new 044 pump with decent loom and relay etc, and made and fitted a junction box on batt (now round post) also have fitted a new act sensor.

Still not sorted have full boost back 17 peak 15 held but get an occasional cough from it, hard to explain but a slight miss not a full blown one.
It has had most sensors replaced new fuel etc.
Is there anything obvious I have missed oh plugs rotor arm and cap have all been cleaned as well.