https://www.nopistons.com/forums/pub...1047683358.gif just installed ap engineering apex pfc to 1989 turbo rx7. Warm up seems fine, drives fine , but when warmed up drops to normal idle about 750rpm smooth, then starts speeding up to 1400-1500rpm then droping down 600-700rpm constantly.

Suspect tps but checking green test plug shows one light out of two on as in workshopmanual . So swiched tps with another car which goes and had new one, still no change. Not sure what to do next ... https://www.nopistons.com/forums/pub...1047683358.gif

does it do the same thing with the stock ecu?

No , But with stock ecu sometimes idle will no drop below 1500rpm, but usually idle was around 850rpm. Car was an auto converted to manual. Have checked BAC solinoid, even removed and sealed off with flange.

When adjusting tps noted that when plunger was almost completely in idle would drop to a steady 750-800rpm but as soon as any load went on motor idle started hunting from 800- 1300 for 30seconds or so then steady out again.

Currently Bac is disconnected . Car starts up cold and idles about 900rpm but when hot idle is about 1300rpm.

Tps with plunger fully in reads .51 ohms fully extended 1.6

when adjusted to read 1v when pluged in ignition on then started hunts constantly when hot. Have not checked voltage where it is now as it was late when we did it and intercooler was back on.