I have a b16a with a crappy pw0 ecu that they sent with the motor, It's throwing a check engine light,rough idle, and no vtech. I figured since that ecu is screwed that a working one would fix most my problem.
I changed the ecu with my friends pw0 ecu and the check engine light went away and the idle went normal but still no vtec.
Any suggestions, thank you

 

check the oil
if it still doesn't work after the engine is warm
inspect the wiring.
removed the solenoid and make sure nothing is clogging it up

 

Thank you