I replaced my stock injectors yesterday with 780cc injectors and when im at about 6000 6500 rpms the needle just bounces between the two, Would this be fixed after a tune ? Or maybe i had installed the injectors wrong?I have a 2003 evolution

 

So...
You installed injectors without a tune? Did you at least reflash the ecu to scale them and ballpark the latencies?

 

Definitely need a tune after changing something like the injectors

 

Injectors need a tune dude.....

What is your AFR Reading??