Turbocharger System Component Inspection

DOHC waste gate solenoid, waste gate actuator, and relief valve test procedures. These are the factory TD04-era waste gate control checks — useful as a baseline reference, but the control pressures below are specific to the stock TD04 waste gate hardware and should not be assumed to carry over to a VF25 waste gate actuator without independent verification.

Waste gate solenoid test

1. Raise vehicle on safety stands and secure.
2. Remove the (black color-coded) vacuum hose from the waste gate solenoid valve as shown in the diagram.
3. Attach vacuum gage as shown.
4. Start engine and allow to warm to operating temperature.
5. Place vehicle into 2nd gear (M/T) or “L” range for A/T vehicles.
6. Run engine RPM to +3500 RPM to activate solenoid.
7. Solenoid must activate at 44–80 kPa (6.4–12 psi) {0.45–0.82 kgf/cm²}.
8. Replace valve if defective.

Waste gate actuator test

1. Connect hand-held vacuum pump as shown in the diagram.
2. Actuator must move at 72 kPa (10 psi) or must be replaced.

Note: Do NOT increase vacuum over 87 kPa (13 psi) or the diaphragm will rupture.

Waste gate solenoid test II

1. Remove solenoid and attach hand pump as shown to the “A” nipple.
2. Connect electrical jumpers as shown.
3. Power engaged: valve open and limited leak.
4. Power removed: valve closed.

Solenoid resistance (ohm) test

Test at ambient temperature.

• Limit: 36–44 Ω (verify printed p.69) — the OCR rendered this as “36-442” with no unit; 36-44 ohms is the most plausible reading given the “Ohm” label on the following line, but the exact figure and unit should be confirmed against a clean copy before use.
• Replace if out of limit.

Relief valve

• Relief valve opening pressure on nipple “B”: opening at 53 kPa (7.7 psi) {400 mmHg}.