VISUAL INSPECTION
Visually inspect all electrical wiring, looking for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and are not pinched or cut. See VACUUM DIAGRAMS article to verify routing and connections (if necessary). Inspect air induction system for possible vacuum leaks.
FUEL PUMP TEST
Turn ignition off. Apply battery voltage to fuel pump check terminal connector. See FUEL PUMP CHECK TERMINAL WIRE IDENTIFICATION table. (Scheme 7) Remove fuel tank cap and listen for fuel pump operation. Pinch fuel hoses by hand and ensure fuel pressure can be felt.
| Application | Wire Color |
|---|---|
| Sonata 2.0L | Green/Yellow |
FUEL PUMP CHECK TERMINAL WIRE IDENTIFICATION
Scheme 7
Scheme 8
- Release fuel pressure. See FUEL PRESSURE RELEASE. Disconnect high pressure fuel hose from top of fuel filter. Cover hose connection using rags to avoid spraying of fuel.
- Using Fuel Pressure Gauge Adapter (09353-24200 ), install fuel pressure gauge to fuel filter. (Scheme 8) Tighten bolt to 18-25 ft. lbs. (25-34 N.m).
- Start engine. Ensure no fuel leakage exists at pressure gauge or connection. Disconnect vacuum hose from fuel pressure regulator, and plug hose end.
- Measure and record fuel pressure at idle. Reconnect vacuum hose, and again measure and record fuel pressure. See FUEL PRESSURE SPECIFICATIONS table. If measurements are not within specification, go to next step. If measurements are okay, go to step 8). FUEL PRESSURE SPECIFICATIONS Engine Application At Idle W/ Vacuum psi (kg/cm 2 ) At Idle W/O Vacuum psi (kg/cm 2 ) Sonata (2.0L) 39 (2.7) 46-49 (3.2-3.4)
- If fuel pressure is low, check for a restricted fuel filter or for leaking fuel to return side. This can be caused by poor seating of valve in fuel pressure regulator or low fuel pump discharge pressure.
- If fuel pressure is too high, check for sticking valve in fuel pressure regulator, or restricted or bent fuel return hose or pipe.
- If fuel pressure does not differ when regulator vacuum hose is connected or disconnected, check for restricted/damaged vacuum hose or fitting, or sticking or poor seating valve in fuel pressure regulator.
- If measurements are okay in step 4), stop engine and ensure fuel pressure gauge reading does not drop. If fuel pressure drops slowly after engine is stopped, an injector is leaking. If fuel pressure drops immediately after engine is stopped, check valve inside fuel pump is not closed.
- After testing is completed, release fuel pressure. See FUEL PRESSURE RELEASE. Disconnect fuel pressure gauge from adapter bolt. Ensure hose connection is covered by a shop towel to prevent fuel spray. Remove adapter bolt, install NEW "O" ring, and replace with original bolt. Apply battery voltage to fuel pump drive terminal. (Scheme 7) Check for leaks.
SFI CONTROL RELAY TEST
| CAUTION | When applying direct battery voltage, ensure voltage is applied to correct terminal to prevent relay damage. |
- Remove control relay. Relay is located behind right kick panel, near ECM. Apply battery voltage across terminals No. 6 (positive) and No. 8 (negative) while checking voltage on terminals No. 1 and 2. (Scheme 9) Battery voltage should exist.
- Apply battery voltage across terminals No. 7 (positive) and No. 10 (negative) while checking continuity between terminals No. 3 and 4. Continuity should exist. Apply battery voltage across terminals No. 3 (positive) and No. 9 (negative) while checking voltage at terminal No. 4. Battery voltage should exist. Replace relay if it fails any test.
Scheme 9
See also:
• ADJUSTMENTS