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Spark Control System Toyota Tercel L30

Testing & Diagnostics 6 illustrations ~773 words

DESCRIPTION

The spark control system helps reduce exhaust emissions by delaying vacuum advance and lowering maximum combustion chamber temperatures. System improves cold engine performance by advancing timing only when the engine is at normal operating temperature. The system includes a distributor or Integrated Ignition Assembly (IIA) with a vacuum advance diaphragm, Bi-metallic Vacuum Switching Valve (BVSV), Vacuum Switching Valve (VSV), High Altitude Compensator (HAC), temperature switch, check valve and jets. Components vary due to application.

Scheme 64

Scheme 64: DESCRIPTION
Scheme 64: DESCRIPTION

Scheme 65

Scheme 65
Scheme 65

Scheme 66

Scheme 66
Scheme 66

Scheme 67

Scheme 67
Scheme 67

COMPONENT TESTING

Note. Note location of BVSV prior to testing. (Scheme 64)- (Scheme 67).

BVSV "A" (TERCEL SEDAN)

  1. Drain coolant. Remove BVSV "A" from intake manifold. Using cool water, cool BVSV to below 77°F (25°C).
  2. On Federal models, blow air into port "J". (Scheme 68) Air should flow from port "L". Heat water to above 106°F (41°C). Blow air into port "J". Air should flow from port "K". Replace valve if defective.
  3. On California models, blow air into upper port. Air should not flow through the valve. Heat water to above 106°F (41°C). Blow air into upper port. Air should flow through the valve. Replace valve if defective. Apply sealant to threads of BVSV and reinstall. Fill radiator with coolant.

BVSV "B" (TERCEL SEDAN M/T)

  1. Drain coolant. Remove BVSV "B" from intake manifold. Using cool water, cool BVSV to below 40°F (104°C).
  2. Blow air into port "M". (Scheme 68) Air should flow from ports "L" and "N". Heat water to above 129°F (54°C). Blow air into port "M". Air should not flow from any ports. Replace valve if defective. Apply sealant to threads of BVSV and reinstall. Fill radiator with coolant.

Scheme 68

Scheme 68
Scheme 68

BVSV (COROLLA CARBURETED)

  1. Drain coolant and remove BVSV. Using cool water, cool BVSV to below 104°F (40°C). Blow air into upper port. Air should not flow through the valve.
  2. Heat water to above 129°F (54°C). Blow air into upper port. Air should flow through the valve. Replace valve if defective. Apply sealant to threads of BVSV and reinstall. Fill radiator with coolant.

CHECK VALVE

Note direction of valve installation. Remove valve. Apply air pressure to one side of valve. Air should flow freely in one direction and be restricted in the other. Replace valve if defective.

JET

Blow air through jet. Replace jet if restriction exists.

DISTRIBUTOR VACUUM ADVANCER (COROLLA CARBURETED & COROLLA FX)

Remove distributor cap and rotor. Apply vacuum to all ports individually and note that advancer moves. Repair advancer if no movement exists.

VACUUM SWITCHING VALVE (COROLLA FX)

Connect battery to VSV terminals. Blow into port "E". (Scheme 69) Air should flow from port "F". Disconnect battery. Blow into port "E". Air should flow from port "G". Replace valve if defective.

Scheme 69

Scheme 69: VACUUM SWITCHING VALVE (COROLLA FX)
Scheme 69: VACUUM SWITCHING VALVE (COROLLA FX)

COOLANT TEMPERATURE SWITCH (COROLLA FX)

  1. Drain cooling system. Remove temperature switch from intake manifold. Cool switch to below 109°F (43°C).
  2. Using ohmmeter, check that continuity exists between switch body and switch terminal. Heat switch to above 131°F (55°C) and note that no continuity exists. Replace switch if defective.

COROLLA (CARBURETED)

  1. Install timing light. Warm engine to normal operating temperature. Check ignition timing. Ignition timing should be 13 degrees BTDC at 950 RPM.Disconnect and plug vacuum hoses from distributor sub-diaphragm. (Scheme 64)- (Scheme 67).
  2. Recheck ignition timing. Timing should be 5 degrees BTDC at 950 RPM. Reconnect vacuum hoses. Remove timing light. If timing is not within specification, individual components must be checked. See «COMPONENT TESTING»(/toyota/tercel/l30-1986-1990/remont/testing-diagnostics/#spark-control-system__component-testing).

COROLLA FX

On Federal models, inspect High Altitude compensator (HAC) system. See HIGH ALTITUDE COMPENSATOR SYSTEM article. On all models, inspect individual components. See COMPONENT TESTING .

TERCEL SEDAN

  1. Disconnect vacuum hose at Integrated Ignition Assembly (IIA) sub-diaphragm. (Scheme 64)- (Scheme 67). Connect a vacuum gauge to sub-diaphragm. Ensure coolant temperature is below 77°F (25°C). Start engine and note vacuum reading while increasing and decreasing engine RPM.
  2. Vacuum reading should remain steady. Operate engine until coolant temperature exceeds 106°F (41°C). Operate engine and note vacuum reading while increasing and decreasing engine RPM.
  3. Reading should vary with manifold vacuum. Remove vacuum gauge and reinstall vacuum hose.
  4. On M/T models, disconnect main diaphragm (outer) hose at IIA and connect to vacuum gauge. With coolant temperature below 104°F (40°C), start engine.
  5. Note that vacuum gauge indicates no vacuum. Warm engine to 129°F (54°C). Accelerate engine to 2500 RPM and note that vacuum is indicated. Remove vacuum gauge and reinstall vacuum hose.
  6. On all models, remove IIA cap, rotor and dust cover. Apply vacuum to both diaphragms and note that advancer moves. Repair as necessary if no movement exists. If system operation was incorrect, individual components must be tested. See «COMPONENT TESTING»(/toyota/tercel/l30-1986-1990/remont/testing-diagnostics/#spark-control-system__component-testing).

See also:
• COMPONENT TESTING

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