idols up and down

Sounds like a vacuum leak If its doing it when you hit the brake possibly the brake booster or the vacuum line to the booster has a leak

I.A.C. >>>If your not sure how to test it,then it'll be less expensive to have someone experienced with E.F.I. diagnose it<<< make sure you Tell them what screws you've turned and parts have been replaced so they don'waste their time and your money.The idle air adjustment screw has a cap on it from the factory for a reason........this is a year and a half late .....but was my guess close? If you can't dazzle them with brilliance , baffle them with bu.......