hi. i have problem with my stock h22a vtec. The vtec will activate only when engine cold, but when the engine is hot after a few minute of ride, vtec can't activate. i try to swap ecu with my friend but it still the saeeme.i test with voltmeter at the vtec solenoid. it shows reading after rev higher more than 5.5k even vtec is not activate . This indicate there is voltage. what is possibly wrong?any one can help?