have this problem with an ea 3 speeder it idles to low if you try to idle it up ittries to stall then revs up then dies down again and soforth idle it back down and it comes good but idles to low 500rpm.
and when you try to rev it ithesitates the revs up doesnt matter wether its in gear or not

sounds like it needs the base ide fixed or the ecu could be stuffing up

tried different ecu out of another car still same

what you drive mate.?pm me

cheers stef