Please help breaking up at high rpms

[John95GST]

ok 95 gst was running great from what was told went to look at it and injector 2 was out so he got stock injectors found out that 660 were in it befor now when i went to drive it it pulls hard till about 5500 to 6000 and breaks up? shoudl i do a walbro 255 will that help? its runnin 14psi or should i get different injectors or could it be something else thanks for your time

 

[John95GST]

Ok I bought v3 my break up at high rpm is gone but no I get random
Misfires at low rpm like will run fun then bam it will start missing is what it feels like if I shut it off then back on its fine again now what did I do I had v3 tuned with stock injectors and stock mass sensor so now I'm puzzled again also did new plugs since it was running lean befor

 

[My1GLaser]

Post a log. It will be 10 times easier to diagnose!

 

[John95GST]

Ok post a log of it running or drive it till it starts spuddering then log?

 

[My1GLaser]

An idle log will work, and let it run long enough to catch in the act! If it doesn't that's fine. A log is worth a thousand words!!!

Does your 2g have a 6 bolt swap by chance?

What plugs did you get and what gap are you running?

 

[John95GST]

im running a 1g cas or the adjustable timeing and forgot to uncheck missfire detection it hasnt done it yet since