VTEC Spool Valve

WARNING: This page is about a different car, the 1994 Acura NSX and 1993 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. See Fig 1 .
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 .

Fig 2: Inspecting VTEC Spool Valve
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If filters are normal, push the spool valve with your finger and check its movement. If spool valve is normal, check the engine oil pressure. See Fig 3 .

Fig 3: Testing VTEC Spool Valve Operation

Courtesy of AMERICAN HONDA MOTOR CO., INC.