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Spark Test: Notes

  1. Remove duct between air cleaner and intake plenum air connector. Disconnect cruise control, accelerator, and throttle cables (automatic transmission only).
  2. Remove 6 hoses from idle speed control pipe. Remove 2 bolts and idle speed control pipe from intake plenum air connector. Remove oxygen sensor wire from clamp. Disconnect hose from PCV pipe. Remove 2 bolts and disconnect PCV pipe with hoses from cylinder head covers and throttle body.
  3. Disconnect hose from intake plenum air connector. Remove 2 bolts, loosen clamps, and remove intake plenum air connector. Remove oil filler cap. Remove 5 nuts from "TOYOTA TURBO" labeled ignition coil pack cover, and lift off cover.
  4. Remove nut and disconnect No. 1 and No. 2 wires from ignition coil and clamp. Move ignition coil pack with bracket out of the way and remove all spark plug wires from spark plugs.
  5. Remove all spark plugs. Install oil filter cap. Install spark plug wires onto the original 6 spark plugs or use several high output spark testers along with spark plugs. See Figure.
  6. If spark plug testers are available, install one on each wire of separate coil packs along with one spark plug to other spark plug lead per coil pack.
  7. If spark testers are not available, install all 6 spark plug wires to the 6 removed spark plugs. Ground each spark plug and/or spark tester securely.
    CAUTION: Ignition coil primary or ignitor circuit damage can result if each spark plug and/or spark plug tester is not securely grounded.
  8. Disconnect solenoid resistor block and cold start injector connector. Cold start injector is on bottom of air intake chamber. Solenoid resistor block is on top of right side shock tower (4-wire connector).
  9. Crank engine and check for consistent Blue spark across plug gaps. See Figure. If all spark plugs and/or spark testers do not fire, check ignition feed to coil pack and ignitor circuits. See IGNITION FEED CIRCUIT TEST under IGNITION COIL in this article.
  10. Verify that camshaft sensor signals are received by ECU. See IGNITOR TEST in this article. Also, verify camshaft sensor moves when engine is cranked.
  11. If only one or 2 spark plugs and/or spark plug testers show an inconsistent spark across the gap, test that particular coil pack for ignition coil primary resistance as well as spark plug wire resistance. See IGNITION COIL RESISTANCE. Ignition high-tension wire resistance should be 25,000 ohms maximum per wire.
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