so theres a Guy I know who threw different EJ18 from a 93 in to his 95 impreza. now I know theres differences in between the 2 motor so thats why I think he has this problem.... he took it to a place and said it was running to rich and thats why it idled high... also when it warms up to normal op it idles very rough as if a misfiring clyinder....I threw my 94 Ecu from a 1.8 it ran better but still idled higher than it should be. it was at 1500 then would drop to 1100. he wouldn't be able to use my old ecu since his car is an automatic. if it is running rich why would it idle so crappy once it was warm. any way to adjust idle air on the 93 1.8's? I know how to on the Ej20G's....

cliff notes
93 Ej18 was put in a 95L...suspected that the ecu is a 95 ecu still and making it idle high then when it warms up it idles some what lower and rough. what could be the problem?

bump help please

Are the coolant lines on the IAC connected? I disconnected mine in an attempt to keep the TB cool during summer months, but it made similar problems to what you describe. Sorry I can't help any more than that.

Jay Storm