Mercury 2003 115 4-strokeEFI Won't Idle

[Sunsetjerry]

Was working fine went out for a ride on the way back she won't idle
Can only start withi half throttle

 

[alldodge]

Most likely the Idle Air Control (IAC) valve
What is your serial number?

 

[Sunsetjerry]

This

 

[alldodge]

No that's emission info
serial number would be a number, letter, and six more numbers

exp: 1A123456

 

[Sunsetjerry]

Where would it be

 

[alldodge]

Edit change that:
https://www.perfprotech.com/mercury-marine-parts-catalog/search
The one below may not be yours, its just an example
https://www.mercruiserparts.com/bam/subassembly/32203/11821/120