i have a civic 93 swap h22a4 turbo wire tuck no vtec works i check the car all wire and its fine when i do the wire tuck car works perfect and someday vtec no works
i check the wire for the ecu to vtec selenoid and its fine the bulb of the pressure of vtec its fine
i discconect the wire of the seleoind and i put a flashlight 12v and the ecu dont send signal and the chip vtec is on..
oil level its fine
no cel codes..
please help me

 

this may seem stupid, but have you checked to ecm ground on the thermostat housing? its two wires with an eyelet coming right out of the harness... had the same problem before and took me like 2 months of sporadic vtec to figure it out