ej22 AT hunting idle

[bbrow632]

Hi all,

I’ve run out of ideas to fix my ej22 idle issue. 
 

a quick run down.  Engine is out of a 98’ legacy AT and is now in a westy with a 5MT Subarugears. 
 

i have changed the following. 
 

IACV, throttle position sensor, Vapor canister purge solenoid valve, temp sensor, cat and both 02 sensors.

i have tried the following. 
 

grounding pin 82 neutral position switch, pin 82 to 12v battery power, grounding pin 81 AT signal wire, Jumping pin 79 to pin 82. 

The engine will idle perfectly for about 9min, until the engine temp reaches 140degrees F, after than the engine will surge by roughly 250 rpm. 

Im at a complete loss. Looking for some guidance, thanks in advance!