I have a strange missfire.

So far i have changed the coil,plugs,phase sensor and crank sensor.

It only seems to be high boost when i have the missfire. If i turn the boost controller off i have no issue but even if the controller is on its lowest setting 0.95 bar it misses.

HKS EVC boost controller

 

get on the rollers, misfires on boost are bad news , the escort cossie has poor wiring to the fuel pump and can give low fuel pressure on boost ( make sure the RR can check your emissions on the rollers ) if it only happens on boost its going to be had to trace off boost.....
you have done the basics so get on the rollers

 

Sounds like an over boost valve kicking in. Standard boost will be less than 0.95 bar and I would imagine an overboost valve kicks in at 1 bar. Just sounds like its coming in a little earlier is all. There is some gadgetry that eliminates the over boost valve, I think its called a fuel cut defender????

Anyhowz, thats my pearl of wisdom from my non existent knowledge of cossies lol.