VTEC Spool Valve

WARNING: This page is about a different car, the 1992 Acura NSX and 1991 Acura NSX. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the 2-pin connector from the spool valve.
Measure resistance between the Yellow (front cylinder head) or Blue/Yellow (rear cylinder head) terminal and body ground. Resistance should be approximately 14-30 ohms. See Fig 1 .

Fig 1: Testing VTEC Spool Valve Resistance
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If the resistance is within specifications, remove the spool valve assembly from the cylinder head and check the spool valve filter for clogging. If there is clogging, replace the engine oil filter and engine oil. See Fig 2 .
If filters are normal, push the spool valve with your finger and check its movement. See Fig 3 . If spool valve is normal, check the engine oil pressure. With oil temperature at 176°F (80°C), oil pressure should be 10 psi (69 kPa) minimum at idle, and 50 psi (345 kPa) minimum at 3000 RPM.

Fig 2: Inspecting VTEC Spool Valve

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 3: Testing VTEC Spool Valve Operation

Courtesy of AMERICAN HONDA MOTOR CO., INC.