unpluged and repluged ecu now idles low

[s13gonwild]

ok so my friend has been having trouble starting his car(car will start but sometimes wont start untill we push start or just leave it there for couple of house..cranks but nothing)..so after replacing injectors...plugs wires..rotor,cap.MAF...so we decide to swap out ecu from my 240 into his(to check is his ecu was causing it)...so we do and when we start it up fine..but then the idle drops down to 600-500..so we decide to swap it back...so we do and same....im just wondering why it is doing this? searched but came up with nothing..i usually search and dont post like this..but i cant fine anything..Also i took it out of my project 240..and i cant start it and see if i will have the same prob now...also why would this happend?

Thanks alot for the help..

[s13gonwild]

anyone? is this really a stupid question?

[Flybert]

Have you even tried raising the idle?

[zero.counter]

You can adjust idle on the ecu and on the back of the A.A.C. valve as well. This, I know is for the ka24e...