Missfire above 3k
 

Ive been trying to chase down an intermittent missfire. Rebuilt engine, about 15 miles so far. In sixth gear the engine starts missing at 3000 rpm. I have replaced the coils, plugs and injector on #1. So i think it could be a direct injector or a cam position problem. Only code i get is #1 cylinder misfire. Any other thoughts as to what i should be troubleshooting? Thanks