Zae Lee

Ok so i bought 95 accord ex. One problem, vtec wont activate. Finally (because the other mechanics where trash) my buddy looked and was like oh heres the problem and connects my colant temp switch. Does that then vtec works. Drove it for like 2hrs then my car jerked really hard and dropped down to second gear. It woulnt shift past 2nd gear. I disconnected the colant temp switch and its shifting through all 4 again. Why??