any idea why my vtec doesnt kick in all the time? Its b20b4 with b16 head, replaced solenoid with one i had before, still same problem, oil level is fine, coolant is fine, once i drive it for awhile it stops kicking in

 

Sounds like its not grtting enough oil pressure. You should have no less than 50psi@3k rpm. The fact that it takes a while (im guessing 15-20min) is most likely due to the oil viscosity thinning as it reaches operating temp

 

https://honda-tech.com/forums/showth...2135&styleid=2

 

I second oil pressure loss. If it works early, the system works. Sounds like external factor like pressure loss. How is the pump?