1990 Suzuki SamuraiFACTORY OEM SERVICE PROCEDURE

System Test

  1. Warm engine to normal operating temperature. Turn engine off. Ensure throttle opener slightly opens throttle valve with engine off and while engine is cranking. If throttle valve was opened, go to step 3).
  2. If throttle valve was not opened, check throttle opener diaphragm. See THROTTLE OPENER DIAPHRAGM  under THROTTLE OPENER SYSTEM (SAMURAI & SIDEKICK) in this article. Replace throttle opener if defective. If throttle opener was okay, adjust throttle opener. See ADJUSTMENTS article.
  3. Note if throttle opener rod retracts within one second after engine starts. If rod retracts, check throttle opener adjustment. See ADJUSTMENTS article. Adjust as necessary. If rod did not retract, go to next step.
  4. Check vacuum hoses to throttle opener. If vacuum hoses are okay, check throttle opener diaphragm. See THROTTLE OPENER DIAPHRAGM  under THROTTLE OPENER SYSTEM (SAMURAI & SIDEKICK) in this article. Replace components as necessary. If components are okay, go to next step.
  5. Check throttle opener vacuum switching valve. See appropriate THROTTLE OPENER VACUUM SWITCHING VALVE (SAMURAI)  under THROTTLE OPENER SYSTEM. If VSV is okay, go to next step. Replace VSV if defective.
  6. Turn ignition on. Check for battery voltage between ground and ECM terminal B14 (Light Green/White wire). ECM is located near glove box on Samurai or upper left corner of instrument panel on Sidekick.
  7. If battery voltage is present, go to next step. If battery voltage is not present, check for defective connection at VSV, defective wiring between ECM and VSV or defective wiring between VSV and EFI main relay (Samurai) or control relay (Sidekick). If wiring and connections are okay, replace ECM and recheck operation.
  8. While cranking engine, check for voltage on ECM connector terminal B14 (Light Green/White wire). If no voltage is present, ECM is okay. If voltage is present, go to next step.
  9. While cranking engine, check for battery voltage on ECM connector terminal B11 (Black/Yellow wire). If battery voltage is present, go to step 10). If battery voltage is not present, check for open or short to ground in Black/Yellow wire between ECM and starter.
  10. Check for defective connection at ECM. If connection is okay, replace ECM and recheck system operation.
Factory Service Tools

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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.

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