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Engine Controls - Basic Diagnostic Procedures: Other Volvo S40 I рестайлинг

Testing & Diagnostics 4 illustrations ~957 words

Cylinder Combustion Pressure Leakage

  1. Run engine until operating temperature is reached.
  2. Remove engine cover. see scheme 1 Remove cover from over ignition coils.
  3. Mark each ignition coil and remove. see scheme 3 Remove spark plugs. Remove system relay from relay box located behind driver-side strut tower. see scheme 9
  4. Disconnect engine speed (RPM) sensor electrical connector. Sensor harness connectors are located on firewall, under cover. see scheme 2
  5. Set cylinder No. 1 at TDC. Connect leakdown gauge to cylinder No. 1 and pressurize cylinder. If leakdown is excessive, see «CYLINDER LEAKAGE DIAGNOSIS»(ref-160011-S18866365022004012100000) table for possible causes. Repair as necessary and go to next step. NOTE: It may be necessary to install components and run engine before all cylinders are checked because engine may cool during testing causing variations in test results.
  6. Repeat procedure for every cylinder. Repair as necessary and go to next step when all cylinders are checked.
  7. Install components when cylinder leakdown test is complete. Tighten spark plugs to 18 ft. lbs. (25 N.m). Tighten ignition coils to 89 INCH lbs. (10 N.m). Install ignition coil cover and engine cover and tighten fasteners to 72 INCH lbs. (8 N.m).
  8. Start engine and check for proper function. Retrieve and diagnose DTCs using scan tool.
Leakage LocationRelated Faulty Component
Exhaust PipeFaulty Exhaust Valve/Valve Seat
Intake Manifold/Throttle BodyFaulty Intake Valve/Valve Seat
Dip Stick Hole/Crankcase VentilationFaulty Piston Ring/Piston
Adjacent CylinderFaulty Cylinder Head Gasket
Radiator/Expansion TankFaulty Cylinder Head, Gasket/Cracked Cylinder Wall

CYLINDER LEAKAGE DIAGNOSIS

Exhaust System Backpressure

  1. Exhaust system can be checked using a vacuum or pressure gauge. Remove oxygen sensor.
  2. Connect a 1-10 psi pressure gauge, and run engine at 2500 RPM. If exhaust system backpressure is greater than 2 psi, exhaust system or catalytic converter is plugged.
  3. If using a vacuum gauge, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold steadily. If vacuum gauge reading slowly drops after stabilizing, exhaust system should be checked for a restriction.

FUEL SYSTEMS

Note. For wire color and terminal identification, see appropriate ENGINE PERFORMANCE WIRING DIAGRAM article.

WARNINGAlways relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components.

Basic diagnosis of fuel system should begin by checking fuel pump operation and fuel pressure.

FUEL SYSTEM PRESSURE RELEASE

See FUEL SYSTEM PRESSURE RELEASE in REMOVAL & INSTALLATION - S40 & V40 article.

Scheme 7

Scheme 7: Testing With Vehicle Stationary
Scheme 7: Testing With Vehicle Stationary

Scheme 8

Scheme 8
Scheme 8

Scheme 9

Scheme 9
Scheme 9
  1. Remove cover over throttle body. Remove aluminum plate from over turbocharger. Remove fuel rail cover. Remove cap from fuel rail schrader valve. (Scheme 7)
  2. Disconnect vacuum hose from fuel pressure regulator and intake pipe. (Scheme 8) Ensure hose is in good condition and not blocked. If any fuel is present in regulator vacuum hose, replace regulator. Clean vacuum hose connection on intake pipe.
  3. Connect Pressure Gauge (999-5011) to Adapter (998-9725). Connect Adapter to Extension (999-5479). Connect assembly to fuel rail schrader valve and lock fitting. Connect a drain hose to Adapter and place in a clean container. Hang pressure gauge vertically. (Scheme 9)
  4. Disconnect vacuum hose from fuel pressure regulator. Start engine. Fuel pressure should rise to approximately 45 psi (300 kPa) immediately. If pressure is correct, go to next step. If not, go to step 8.
  5. Connect Vacuum Pump (999-5757) to pressure regulator. Create vacuum. Fuel pressure should drop, but not below approximately 35 psi (240 kPa). Release vacuum. Pressure should rise to 49 psi (309 kPa) immediately. Create pressure with pump. Fuel pressure should rise. DO NOT raise fuel pressure above 55 psi (380 kPa). Release pressure. Fuel pressure should return to 49 psi (309 kPa) immediately. If pressure regulator functions properly, go to next step. If not functioning properly, replace regulator. See «FUEL PRESSURE REGULATOR»(ref-159330-S33093835752003112600000) in REMOVAL & INSTALLATION - S40 & V40 article. Repeat procedure. If regulator now functions properly go to next step.
  6. Check residual fuel pressure. Starting pressure is approximately 49 psi (309 kPa). Switch off engine and monitor fuel pressure for 20 minutes. Pressure must not drop below 29 psi (200 kPa). If pressure drops too much, inspect fuel system for leakage. Repair and repeat residual pressure test.
  7. Remove pressure testing equipment when test is complete. Install cap on fuel rail schrader valve. Start engine and ensure proper function. Install throttle body cover.
  8. Raise and support vehicle. Remove splash guard from fuel line. (Scheme 10) NOTE: Do not hang fuel filter by fuel line.
  9. Loosen fuel filter clamp. Move filter downward and remove cap on schrader valve. Attach fuel gauge and pressure testing equipment to valve. Lower vehicle and hang gauge vertically. see scheme 8 NOTE: Fuel pump relay is integrated into system relay. Rear fuel pressure regulator is integrated into fuel pump.
  10. Access relay box in engine compartment behind driver-side strut tower. Remove relay 2/14 (System Relay). Bridge terminals 30 and 87 of relay socket to start fuel pump. see scheme 9 Fuel pressure must rise to approximately 62 psi (430 kPa) immediately. If pressure is incorrect replace fuel pump. See «FUEL PUMP»(ref-159330-S25978830482003112600000) in REMOVAL & INSTALLATION - S40 & V40 article. Go to next step.
  11. If pressure is correct at rear regulator, but pressure reached correct value slowly at engine regulator, check fuel line for pinching or damage. Repair as necessary. If fuel line is OK, replace fuel filter. Go to next step.
  12. If pressure is correct at regulator but incorrect at engine regulator, replace engine pressure regulator. See «FUEL PRESSURE REGULATOR»(ref-159330-S33093835752003112600000) in REMOVAL & INSTALLATION - S40 & V40 article.
  13. Remove pressure testing equipment when test is complete. Install cap on fuel rail schrader valve. Start engine and ensure proper function. Install throttle body cover.

Scheme 10

Scheme 10
Scheme 10

DISTRIBUTORLESS IGNITION SYSTEM

For system diagnosis and testing, see applicable tests.

IDLE SPEED & IGNITION TIMING

Note. Idle speed and ignition timing can be checked, but are not adjustable.

Note. For CO level, see IDLE SPEED & CO LEVEL in ON-VEHICLE ADJUSTMENTS - S40 & V40 article.

IDLE SPEED

Normal idle speed is 750 RPM.

IGNITION TIMING

Ignition timing is 9-15° BTDC.

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