Home ReviewsRefund
Home/Honda/Passport/Honda Passport I (1993-1997)/Repair manual/Testing & Diagnostics/Engine Controls - Basic Testing - 2.6L: Diagnosis
Contents Wiring diagrams Section: Testing & Diagnostics All sections

Engine Controls - Basic Testing - 2.6L: Diagnosis Honda Passport I

Testing & Diagnostics 4 illustrations ~477 words

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 not pinched or cut. See VACUUM DIAGRAMS - 2.6L article to verify routing and connections (if necessary). Inspect air induction system for possible vacuum leaks.

FUEL PRESSURE & FUEL PUMP RELAY TEST

Note. Begin basic fuel system diagnosis with testing fuel pressure.

Scheme 46

Scheme 46: Fuel Pressure
Scheme 46: Fuel Pressure

Scheme 47

Scheme 47
Scheme 47

Scheme 48

Scheme 48
Scheme 48

Scheme 49

Scheme 49
Scheme 49
  1. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(ref-15943-S17246973812000122900000). Install a fuel pressure gauge between fuel pressure regulator and fuel distributor pipe. (Scheme 46) Bleed air from fuel line going to pressure gauge.
  2. Unplug fuel pressure regulator Vacuum Switching Valve (VSV) connector on right side fender skirt. This is a 4-wire connector with Black and Blue wires in harness. ECM controls VSV to cut vacuum to fuel pressure regulator during hot engine starts.
  3. Start engine and measure fuel pressure at idle. Disconnect fuel pressure regulator vacuum hose. Note fuel pressure at idle with vacuum hose disconnected (no vacuum). Fuel pressure should be 42 psi (3.0 kg/cm 2 ). See «FUEL PUMP PERFORMANCE»(ref-15943-S35615826512000122900000).
  4. If fuel pump pressure is low, check for fuel leaks, restrictions in intake side of fuel pump, leaking injectors, faulty pressure regulator or faulty fuel pump. If fuel pressure is high, check for restrictions in return line to tank or faulty pressure regulator. If pressure does not change when pressure regulator is disconnected, replace pressure regulator.
  5. Reconnect pressure regulator vacuum hose and check fuel pressure (with vacuum). Fuel pressure should be 35 psi (2.4 kg/cm 2 ). Apply battery voltage to VSV connector Blue wire terminal, and ground Black wire terminal (with vacuum). (Scheme 47) Fuel pressure gauge should read about 42 psi (3.0 kg/cm 2 ). If fuel pressure is not within specification, check for defective VSV.
  6. Disconnect and plug vacuum hose from fuel pressure regulator. Stop engine and ensure fuel pressure remains greater than 35 psi (2.4 kg/cm 2 ) for 4 minutes after engine stops.
  7. If pressure drops, check for leaking injectors, faulty pressure regulator or bad check valve in fuel pump. If engine does not start, by-pass fuel pump relay to check for fuel pressure.
  8. Remove fuel pump relay from underhood fuse/relay box. Connect a fused jumper wire between terminals No. 1 and 3 of fuel pump relay connector in fuse block. (Scheme 48)and (Scheme 49).
  9. If fuel pump does not operate, check for battery voltage to terminal No. 3. If battery voltage is present, check for open in fuel pump circuit. If fuel pump operates with jumper wire installed, check fuel pump relay and relay energizing circuit. Repair as necessary.

TROUBLE SHOOTING CHARTS

Note. Trouble shooting charts for 2.6L 4-cylinder Passport are not available from manufacturer.

See also:
• ADJUSTMENTS - 2.6L

More articles — Engine Controls - Basic Testing - 2.6L