im new to here and i am looking for someone that might know what the hell is wrong with my car i have a 2nd gen non turbo its just a coupe well when i go full throttle it starts to like bog down at 3500 rpms and if i let off and only go like 1/4 throttle it will take off and start to haul *** like it used to if anyone knows what i can do to fix it please let me know my email is twitch1818@yahoo.com

 

It sounds as though you are talking about the 3500 / 3800 rpm hesitation. What's happening is as your car is activating the secondary injectors they're not getting enough voltage to open at the rate you're trying to open them at. The common solution to this is to add grounds to both the engine and ecu. There is a recent post on regrounding here: https://www.rx7club.com/2nd-gen-archive-72/grounding-how-thorough-discriptive-199558/

You may also want to make sure that your 5/6th ports are opening right on your series 4 (86-88) through the split air pipe that comes from the cat to the acv.