Does anyone know what you can do so that the boost is at exactly what you set it to be?

For example: Data set 1 is set with PRI @ 10 PSI and SEC @ 11 PSI. Now it's pretty much dead on the boost most of the time but then once in a while it would go up to 12, 13 PSI.

Data set 2: PRI @ 12, SEC @ 13, now this almost go up to 14 or even 15 most of the time.

Should vent learn be turn off??? I've heard no, it's not a good idea but then how do you really effectively control boost with EFI?

Thank you.

 

I'm not too keen on the pms either but when Doug from EFI was programing mine he set the vent learn to the on position.