Spark Control (SC) System Preliminary Inspection: Tercel

1990 Toyota Tercel Base, 2D Coupe, StandardSECTION Tercel
  1. Disconnect vacuum hose at distributor sub-diaphragm (inboard hose). See Figure. 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) vacuum hose 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 distributor cap, rotor and dust cover. Apply vacuum to both diaphragms and note that distributor advance moves. Repair as necessary if no movement exists. If system operation is not as described, test individual components. Test BVSV "A", BVSV "B" (M/T), restrictor and check valve.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.