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Test A - No Start

NOTE: This condition may be caused by the terminals spreading open at the neutral safety switch connector. Follow this procedure: Locate and remove the neutral safety switch 4-way connector at the left side of the transmission. Check terminals for spreading condition. If necessary, insert small screwdriver between rubber connector and terminal close gap. If this does not correct the condition, proceed with TEST A.
  1. Try to start engine. If engine does not crank, check for excess fuel in cylinders (hydraulic lock) and check the starting/charging system. If engine cranks, but does not start or continue to run, proceed with test.
  2. Disconnect spark plug wire to any cylinder. Connect spark tester between plug wire and engine ground. Crank engine and check for spark. If spark is produced, go to step 13). If not, go to next step. Reconnect spark plug wire to plug.
  3. Remove high tension coil wire from distributor and install spark tester. Check for spark while cranking. If spark is produced, service or repair TFI ignition system. If no spark, go to next step.
    Fig 1: TFI Module Circuit Diagram
    G21650
  4. Turn ignition off and wait for 10 seconds. Disconnect 60-pin connector at ECA. Inspect for damaged pins, corrosion, or loose wires. Repair as required. Install breakout box (timing switch in "Computed" position). Turn ignition on (engine off). With DVOM on 20 volt scale, measure voltage from box pin 37 to pin 40 and from box pin 57 to pin 60. If either reading less than 10.5 volts, perform Test B. If readings are 10.5 volts or greater, continue test.
  5. Turn ignition off and wait 10 seconds. With DVOM on 200 ohm scale, measure between box pin 16 to TFI connector (ignition ground). If resistance is 5 ohms or greater, repair harness and repeat Quick Test. If resistance is less than 5 ohms, go to next step.
  6. Reconnect 60-pin connector at ECA. With breakout box still connected, set timing switch to "Dist" position. Try to start vehicle. If vehicle starts, go to step 10). If not, go to next step.
  7. Turn timing switch to "Computed" position. Set DVOM on 20 volt scale and measure from box pin 36 to chassis ground while cranking engine. If voltage is 3-6 volts, EEC system is okay. Service TFI ignition system. If voltage is less than 3 volts or greater than 6 volts, continue test.
  8. Turn ignition off and wait 10 seconds. Disconnect 60-pin connector at ECA. Disconnect TFI. With DVOM on 200,000 ohm scale, measure resistance from box pin 36 to pins 16, 20, 26, 40 and 60 in turn, for short to ground; from box pin 36 to pins 37 and 57 in turn, for short to power; from box pin 36 to pin 56 for short to PIP. If any reading is less than 10,000 ohms, repair short and repeat test if vehicle does not start. If all readings are 10,000 ohms or more, go to next step.
  9. Turn ignition off and wait 10 seconds. Reconnect 60-pin harness at ECA (TFI still disconnected). With DVOM on 200 ohm scale, measure resistance from box pin 36 to pins 37 and 57 for short to power; from box pin 36 to pins 40 and 60 for short to ground. If any reading is less than 5 ohms, replace ECA and repeat Quick Test. If all readings are 5 ohms or more, continue test.
  10. With DVOM on 20 volt scale, measure voltage from box pin 56 to pin 16 while cranking engine. If voltage is 3-6 volts, remove breakout box and replace ECA. Repeat Quick Test. If voltage is less than 3 volts or more than 6 volts, go to next step.
  11. Turn ignition off and wait 10 seconds. Disconnect 60-pin connector at ECA. With DVOM on 200 ohm scale, measure resistance from box pin 56 to PIP circuit of TFI connector. If resistance is 5 ohms or greater, repair open and repeat Quick Test. If resistance is less than 5 ohms, continue to next step.
  12. With ECA and TFI harnesses still disconnected and ignition off, set DVOM on 200,000 ohm scale. Measure resistance from box pin 56 to pins 16, 20, 40 and 60 in turn, for short to ground; from box pin 56 to pins 37 and 57 in turn, for short to power; from box pin 56 to pin 36 for short to spark output. If any resistance is less than 10,000 ohms, service PIP circuit. If all resistances are greater than 10,000 ohms, service TFI ignition system.
  13. Turn ignition off and wait 10 seconds. Disconnect 60-pin connector at ECA and check for damaged pins, corrosion and loose wires. Service as required. Install breakout box (timing switch at "Computed" position). Reconnect 60-pin connector at ECA. With DVOM on 20 volt scale, measure voltage from box pin 36 to chassis ground while cranking engine. If voltage is less than 3 volts or greater than 6 volts, go to step 10). If voltage is 3-6 volts, go to next step.
  14. Disconnect electrical connectors from both injectors. Connect a pressure gauge to Schrader valve on fuel rail. Note initial pressure reading. Observe pressure gauge while pressurizing fuel system. Pressurize system by turning ignition to "Run" position for 1 second, then off for 10 seconds. Repeat this procedure 5 times. Turn ignition off and wait 10 seconds. Reconnect injectors. If pressure increased from initial reading, proceed to step 16). If pressure did not increase, proceed to next step.
  15. Locate fuel pump inertia switch in left rear of vehicle. Push button on inertia switch to reset. If switch will not reset, replace switch and repeat step 14). If button was on, go to TEST M - FUEL PUMP CIRCUIT (INERTIA SWITCH)  . Observe pressure gauge while pressurizing fuel system. If fuel pressure increases, repeat Quick Test. If fuel pressure does not increase, go to TEST M - FUEL PUMP CIRCUIT (INERTIA SWITCH)  .
  16. With injector wiring harnesses disconnected, pressurize fuel system and turn ignition off. Wait 2-5 seconds for pressure to stabilize. Fuel pressure should be 35-45 psi (2.5-3.0 kg/cm2 ). If pressure is not correct, check fuel system. If pressure reading is correct, proceed to next step.
  17. Wait 2 minutes after reading pressure gauge in step 16). Note pressure drop. If pressure drops more than 4 psi (.3 kg/cm2 ) in 2 minutes, check for hydrostatic lock or fouled spark plugs. If pressure drops less than 4 psi (.3 kg/cm2 ) in 2 minutes, go to next step.
  18. Pressurize the fuel system and verify fuel quality (no water or air in fuel). Disable the electric fuel pump by disconnecting the fuel pump relay. Crank engine for 5 seconds. Take a fuel pressure reading at the end of the cranking period. If fuel pressure is 10-20 psi (.7-1.4 kg/cm2 ), No Start problem is not related to the EEC system. If pressure was more or less than specified; or if pressure was correct and engine runs rough or misses, continue with testing.
    NOTE: A cold engine will have a greater pressure drop than a warm engine. Drop on a 200°F (93°C) engine is about 10 psi (.7 kg/cm2 ) in 5 seconds. Drop on a 60°F (16°C) engine is about 20 psi (1.4 kg/cm2 ) in 5 seconds.
    Fig 2: Injector Circuit Diagram
    G1181
  19. Turn ignition off and wait 10 seconds. Install breakout box. Using a non-powered 12 volt test lamp, connect lamp between box pins 37 and 58. Crank engine and note results. Then connect test lamp between box pins 37 and 59. Crank engine and note results.
  20. If test lamp does not glow on 1 or both tests, verify that battery voltage is recorded at box pin 37. If voltage is not present, repair wire or replace battery. If voltage is present, replace ECA and repeat Quick Test. If test lamp glows brightly on 1 or both tests, check injector circuits for short to ground. If no problem is found, replace ECA. If test lamp glows dimly on both tests, continue test.
  21. Turn ignition off and wait 10 seconds. Remove test lamp and disconnect fuel pump relay. Using a DVOM set on 20 volt scale, measure voltage between the same pins tested in step 19) while cranking engine. If the difference between the voltage readings is 1 volt or greater, disconnect ECA and inspect for corroded or damaged pins. Reconnect ECA and retest. If voltage readings still vary 1 volt or more, replace ECA and repeat Quick Test. If voltage difference is less than 1 volt, circuits are okay. Continue test.
  22. Reconnect fuel pump relay. Turn ignition off. Disconnect electrical connector at injector 2. Set DVOM on 20 ohm range and measure resistance between pins 58 and 37 of ECA connector. Record reading. Disconnect electrical connector at injector 1 and reconnect connector at injector 2. Measure resistance between pins 59 and 37. Record reading.
  23. If both readings in step 22) are not 2.0-3.5 ohms, check wiring harness on injector(s) and repair as required and repeat Quick Test. If wiring harness(es) is/are okay, replace injector(s). If both readings are correct, circuits are okay. Continue test.
  24. With ignition off, disconnect both injector electrical connectors and connect pressure gauge to Schrader valve. Pressurize fuel system. Connect electrical connector at injector 1. Crank engine for 5 seconds and record pressure reading immediately after end of crank cycle. Repeat procedure on injector 2. Pressurize fuel system after disconnecting injector and before connecting injector 2.
  25. If both readings in step 24) are not within 4 psi (.3 kg/cm2 ) of each other, replace injector(s) that is/are incorrect. Reconnect injectors and repeat Quick Test. If both readings are acceptable, check for fuel contamination or other engine malfunctions and test again. If problem remains, disconnect ECA connector and check for corroded or damaged pins. Retest. If problem still exists, replace ECA and repeat Quick Test.
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