IAE and CFM engines are different when doing manual starts. This is due to the 30 seconds of dry cranking required by the IAC engine. Consequently, fuel goes on a different speeds. I recall it's around 20% for CFM and around 35 for IAC. The CFM is purely based on N1, where the IAE is both N1 and a 30 second rotation time. Of course, it's been a while but that's how I recall it.