smokinvtecCRX18

my friend has a 92 hatch he has a 94 gsr in it and he has had it for about 9 months now and about 3 weeks ago the vtec just stoped working. he has always changed the oil on time and it is full of oil, the oil pressure line is good, the engine was throwing a code 22 that code is vtec sylinoid / pressure switch, although we believe that the vtec sylinoid was good(we tested it by running a 12volt wire from the pos. on the battery to the vtec sylinoid and it clicked so supposedly it was good, the ground on the sylinoid is good, the ecu is in good shape, and the car is always been warmed up when we check it for vtec. we recently took the car to a respectible import shop that installed the motor. they asured us that the sylinoid was bad. we had put our friends 94 integra gsr vtec sylinoid on the motor and still no vtec. but they said that was what it was so, them being the professionals we were like ok. and they put it on and they said it had vtec again, and we drove the car and you can hear vtec a little bit but it is really quiet, and before it was loud i mean when it kicked in you could make no mistake about hearing it. so we are bedaffeled on what is causeing this problem, if the knock sensor on the oil pressure line is bad wouldnt that throw a code or if it was shorted out wouldnt that throw a code? has this happened to anybody else because all of the people around where we live have never had this problem. any help would be apreciated, thanks