have a 99 sti type r running simtek ecu so no maf sensor, car is hunting for idle constantly, took iac off and cleaned but looks like it has a wear mark on the plunger and so is possibly not closing properly, if it actually does, will this need replacing? and if so where can i get 1 and what sort of dosh am i looking at?

 

This seems to be common problem with them.

https://www.scoobynet.com/general-te...imtek-ecu.html

Personally i would take it to the person who mapped it and see what they can do before buying new bits.

 

I had hunting problems when i had Simtek. Simtek hasn't got Closed loop idle control thats why idle is always funny.

 

so will this not be able to be resolved?