Fuel Pressure Regulator Control Solenoid Valve (Turbo Models)
- Label and remove vacuum hoses from solenoid valve. Disconnect wiring harness. Connect vacuum pump to nipple where Black vacuum hose was connected. Leave pump connected throughout procedure.
- Apply vacuum and ensure valve leaks. Plug nipple where Blue-striped hose was connected. Apply vacuum and ensure vacuum holds. Remove plug from Blue-striped hose nipple. Apply battery voltage across valve terminals. Apply vacuum and ensure vacuum holds.
- Using an ohmmeter, check resistance across terminals of solenoid. Resistance should be 36-46 ohms at 68°F (20°C). If resistance is not within specification, replace solenoid valve.
- If resistance is within specification, disconnect solenoid harness connector. Turn ignition on. Using DVOM, measure voltage between harness connector terminal (Red wire) and vehicle ground.
- If battery voltage is present, go to step 6). If battery voltage is not present, inspect and repair circuit between MFI relay and solenoid. If circuit is okay, inspect MFI relay. See RELAYS under MOTORS, RELAYS & SOLENOIDS. MFI relay is located near ECM, behind radio, under console.
- Disconnect ECM connector. See ENGINE CONTROL MODULE (ECM) LOCATION table under COMPUTERIZED ENGINE CONTROLS. Connect jumper wire between ECM terminal No. 6 and vehicle ground. See Figure . Using DVOM, measure continuity between solenoid harness connector terminal Blue/Red wire and vehicle ground.
- If continuity does not exist, check and repair circuit between solenoid and ECM. If continuity exists and all preceding tests do not show any system or component malfunction and ECM is suspected, substitute ECM with known good component and retest.