hi guys , is there a proper procedure when flashing ?

my evo is really stock with only a o2 housing , downpipe , test pipe and a catback.
the car has a previous unknown tune. drive fines but not great

i was able to grab the stock evo 9 rom from http://evoecu.logic.net/wiki/Downloads

correctly input the immo code with 0x starting in the edit section on ecuflash

loaded it up and the car turns over and fires up , however idles drops to 0 and dies.
i than switch back to the tuned rom on the car and all is fine.

am i doing something wrong ?

 

Does your EvO have larger injectors?

Wonder if there is a injector scaling issue?

 

they are stock . I did adjust the biss few weeks ago to have a more desirable idle with ac on. Not sure if that has anything to do with it