I started my new motor and it does not want to idle and it seems to be misfiring really badly. It threw 2 codes a Multi Cyl Misfire P0300 and P0031 H02S1 HTR(B1). The car used to be a stock motor with Crawford intake and headers, AAM fuel system with 440cc injectors, vortech kit with 3.33 pulley, split sec box. It now has 8.8 to 1 weisco pistons, eagle rods, 550cc injectors, JWT cams, Im running 1 step colder plugs, same headers, intake and vortech kit. When I crank it up it will go lean then it will start dropping idle till it shuts off this whole time misfiring bad while trying to idle. I’m not sure what the problem is. Do you half to recalibrate the mass air meter for injectors or setup the split sec box? Is there something I need to do for the new cams? When I try to level out the RPM with the throttle it does not react very quick at all, then it will flare up to 3000 RPM's. Is there something I need to adjust or change to make it run correctly?

Thanks Matt

 

https://my350z.com/forum/showthread....=1#post2456882

check this thread.