VTEC Spool Valve

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1999 Acura NSX-T, 1999 Acura NSX, 1998 Acura NSX-T, 1998 Acura NSX, and 1997 Acura NSX-T. 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 Blue/Yellow terminal and body ground. Resistance should be approximately 14-30 ohms. See Fig 1 .
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. If spool valve is normal, check the engine oil pressure. See Fig 3 .

Fig 1: Testing VTEC Spool Valve Resistance

Courtesy of AMERICAN HONDA MOTOR CO., INC.

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.