Why would the vtec stop working on a 1995 acura integra gsr?

Answer 1

VTEC could stop working for a number of reasons:

Oil Pressure Sensor: Can prevent VTEC from engaging if oil pressure is insufficient (normal operation), or could incorrectly report low oil pressure (faulty operation)

VTEC Solenoid: This solenoid opens to route oil through the passages in the head that provide oil pressure to engage the VTEC cam followers. If your oil has sludge or foreign material in it, the VTEC solenoid can become clogged and fail to provide enough pressure to allow VTEC to engage.

Wiring: The wires that link the oil pressure switch or the VTEC solenoid to the computer could have been damaged; inspect the wiring as best you can.

Computer: The computer can detect problems and put the engine into "limp mode", which can disable VTEC and lower the rev limiter to prevent damage to the valvetrain or other components of the engine if a problem is detected. This should be accompanied by a check engine light. Since your car is OBDI do a Google search to find out how to read your codes. There is information out there that will tell you how to get the computer to display the code(s) and whether they are displayed by a light on the computer, or flashed out on the CEL, or displayed in another manner.