I have a rebuilt street ported motor, the car starts up fine, then the idle searches and usually lands at 1100rpms, stays there for a few minutes then begins surging between 800-1500rpms, any ideas?

 

vacuum line or tps is off...that would be my guess

 

Your throttle body air bleed settings are probably off for the new motor. The ISC causes the idle to bounce up and down like that (white plug about midway on the back side of the upper intake manifold.) Try to adjust your bleed screw underneath the throttle body. Close it more or completely close it. Are you using a Power FC by any chance?

 

Im using the power fc. The bled screw is completely closed. The idle finally settled at 1100rpms again for 10 minutes, so I hopped in and took it around my residential side road, when I got back the idle sat at 2100 rpms and didnt drop at all now.

 

Have you done the "PFC Idle Learning" procedure?

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/idle-rock-solid-now-isnt-solid-what-could-252560/

 

I checked the TPS and its within range, Im going to try the pfc learning procedure

 

ah, now the car hardly even runs at all, once I reset the ecu. I need to get all the 3bar map sensor settings, and the injector settings too.

 

I've never used a PFC personally, but I see people sharing maps so I assume there is a way to save it off. You didn't have your map saved?

 

it was a basic base map with the setting for the 3 bar, 850s, 1680's already set, thats all

 

You may have to disconnect the ISC if it's a big street port. I finally had to do that to my car yesterday and it's fine now.
Michel