i have a 92 civic dx with a d15b7. have had prob for a while. runs good but surges during acceleration. has long tube apex header and a cold air kit. had to replace computer because it is a 5 speed but had a computer for an automatic. readjusted high idle and replaced iac. just want it to run like it should. it is sluggish and surges untill it hits 3200 rpm. thain it runs great. what can i do to fix it?