Confused !!

You say AFR 13.5 - I understand this.

But what does 9 to 10 mean ?

I reckon your injectors are not suitable for what you want them to do.
They may be good for power but idle will be a problem !

In this situation, you must either ...

1) accept a rich lumpy idle

2) lower the fuel pressure (which will reduce top end fuelling too !)

3) use a higher idle speed to keep injectors in usable working range.


Are you using grey injectors by any chance ?