I have a S-5 jspec turbo in my 82 FB. I running it with a jspec N-374 ECU. It has all the emissions equipment removed, a walbro 255, and 3 inch dp and exhaust system, other than that it is stock. When i start it cold it idles at 1500 rpm the first 30 seconds or so then drops to about 850. Then it usually surges back and forth between 850 and 1200. Doesnt surge when its at 1500. Also sometimes it will drop down to 850 and hold rock steady until i tapped the throttle. So i think that eleminates a vacuum leak. I have adjusted the tps twice to 1k ohms while it was warm.

Is it possiblily related to the walbro over running the injectors and the computer trying to play catch up.. Other than this small issue it runs great, pulls full boost from second gear and on. Starts while hot or cold, It has a new bosch oxygen sensor along with new plugs and wires. Just trying to iron out this last bug thanks for the help