hi all! I have an 89 supra bone stock 7mgte. just started acting up. if I try to hold a rev at like 2000 itll cut out to around 1000 and then pick backup to 2000 and back down and so on without me changing my throttle input. if I try to hold the rev at 2000 itll bog then come back and bog again and itll do it over and over. I just noticed it when I changed my oil. when I search for the problem I just find a lot of ppl whos supras wont rev past a few k-rpm. mine will rev right up I just cant hold it there. looking for some advice from anyone who has experienced this prob and fixed it. tps,cps, afm, ignition, just lookin for a place to start. thanks