thanks guys, i have contemplated drilling the brass sleave out but i don't want swarf in me inlet and its harder than the alloy that surrounds it so i'll damage the inlet trying to lever it out
I'll check the map sensor as it seems like a likely trouble spot but can't disconnect the amal valve as its only already running a bleed valve.
will a diagnostic check at a garage maybe help? or are the diagnostic ports on these older efi systems not too great?