Im having the same problem with my 94gsr, mycar runs fine when cold but once it warms up it will not engage vtec and my rpms start jumping when ihit around 3000 rpms.solenoid and pressure switch is working fine.

 

Im having the same issue with my 94 gsr.ive checked the solenoid pressure switch screens everything is fine. When my car is cold it runsgreat as soon ascar warms up to opperating temp vtec willnot kick in and rpms start jumping at around 3000 to 3500 rpms.with no vtec.