B16A VTEC questions

[xips(86CRXSI)]

Can anyone tell me what components tell the ecu to kick on the vtec in my car? Vtec is coming on sometimes and not sometimes and a couple times it was engaging and disengaging as I was accelerating. Also it doe's not seam to engage at the correct rpm, its kicking on at like 6000 rpm. Thanks. Ps. I'm not getting any codes.

 

[AHHVTEC]

well it should kick on from 5500 to 6000 rpm just depending but for vtec to work right it need to be at the right temp and it needs oil pressure and make sure there is enough oil in the motor and it needs a vtec ecu witch im sure you have and it also needs to be above 20 mph

 

[xips(86CRXSI)]

Thanks