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Engine Controls - Trouble Shooting - No Codes: Diagnosis Mazda MX-5 NB рестайлинг

Testing & Diagnostics ~450 words

SYMPTOM DIAGNOSIS

CAUTIONWhen battery is disconnected, vehicle computer may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURE - MAZDA article in GENERAL INFORMATION before disconnecting the battery.

Symptom checks cannot be used properly unless problem occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in BASIC DIAGNOSTIC PROCEDURES article and appropriate SELF-DIAGNOSTICS article were performed before diagnosing a symptom. Following symptoms are available for diagnosis

  1. «A/C ALWAYS ON OR COMPRESSOR RUNS CONTINUOUSLY»(ref-151888-S22448674242003010900000)
  2. «A/C DOES NOT TURN OFF DURING WIDE OPEN THROTTLE (WOT)»(ref-151888-S26836174032003010900000)
  3. «A/C DOES NOT WORK SUFFICIENTLY»(ref-151888-S40268872012003102300000)
  4. «COOLING SYSTEM CONCERNS - OVERHEATING»(ref-151888-S15674819242003102300000)
  5. «COOLING SYSTEM CONCERNS - RUNS COLD»(ref-151888-S21594147202003102300000)
  6. «CRANKS NORMALLY BUT WILL NOT START»(ref-151888-S11279917782003010900000)
  7. «ENGINE NOISE»(ref-151888-S23649753882003010900000)
  8. «ENGINE STALLS, QUITS, RUNS ROUGH, MISSES, BUCKS, JERKS, HESITATES, STUMBLES OR SURGES DURING ACCELERATION OR CRUISE»(ref-151888-S35627720072003010900000)
  9. «ENGINE RUNS ROUGH OR ROLLING IDLE»(ref-151888-S41465713252003010900000)
  10. «ENGINE STALLS AT IDLE OR JUST AFTER STARTING»(ref-151888-S22615087772003010900000)
  11. «ENGINE VIBRATION»(ref-151888-S09594920782003010900000)
  12. «EXHAUST SMOKE»(ref-151888-S09123288352003010900000)
  13. «EXHAUST SULPHUR (ROTTEN EGG) SMELL»(ref-151888-S39840022782003010900000)
  14. «FAILS EMISSIONS TEST»(ref-151888-S41626318172003010900000)
  15. «FAST IDLE OR RUN ON»(ref-151888-S34570577472003010900000)
  16. «FUEL DOES NOT SHUT OFF PROPERLY»(ref-151888-S19617441932003102400000)
  17. «FUEL ODOR IN ENGINE COMPARTMENT»(ref-151888-S35678186592003010900000)
  18. «HARD TO START, LONG CRANK, ERRATIC CRANK OR ERRATIC START»(ref-151888-S39250770142003010900000)
  19. «KNOCKING OR PINGING DURING ACCELERATION OR CRUISE»(ref-151888-S21126694202003010900000)
  20. «LACK OR LOSS OF POWER DURING ACCELERATION OR CRUISE»(ref-151888-S25327900792003010900000)
  21. «LOW IDLE OR STALLS DURING DECELERATION»(ref-151888-S25080746862003010900000)
  22. «MIL ILLUMINATED INCORRECTLY»(ref-151888-S15413117442003102400000)
  23. «OIL CONSUMPTION EXCESSIVE»(ref-151888-S27374936632003010900000)
  24. «POOR FUEL ECONOMY»(ref-151888-S25005728552003010900000)
  25. «SLOW RETURN TO IDLE»(ref-151888-S11348957622003010900000)
  26. «SPARK PLUG CONDITION»(ref-151888-S05360223782003102400000)
  27. «WILL NOT CRANK»(ref-151888-S07588292812003010900000)

FAILS EMISSIONS TEST

  1. Check for leakage or blockage of vacuum lines.
  2. Check for cooling system malfunction.
  3. Check for spark plug malfunction.
  4. Check for air leakage from intake manifold.
  5. Check for erratic or no signal from CMP sensor.
  6. Check for inadequate fuel pressure.
  7. Check for PCV valve malfunction or incorrect valve installation.
  8. Check for EGR valve malfunction.
  9. Check for exhaust system clogging.
  10. Check for fuel tank ventilation system malfunction.
  11. Check for charcoal canister damage.
  12. Check for air cleaner element clogging or restriction.
  13. Check for throttle body malfunction.
  14. Check for ignition coil or related circuit malfunction.
  15. Check for Improper air/fuel mixture ratio control operation.
  16. Check for excessive carbon built up in combustion chamber.
  17. Check for improper engine compression.
  18. Check for improper valve timing.
  19. Check for catalyst converter malfunction.
  20. Check for engine internal parts malfunction.

INTERMITTENT PROBLEM DIAGNOSIS

Intermittent fault testing requires duplicating circuit or component failure to identify problem. On some systems, these procedures may lead to computer setting a fault code which may help in diagnosis.

If problem vehicle does not produce fault codes, monitor voltage or resistance values using a DVOM while attempting to reproduce conditions causing intermittent fault. A status change on DVOM indicates a fault has been located.

Use a DVOM to pinpoint faults. When monitoring voltage, ensure ignition switch is in ON position or engine is running. Ensure ignition switch is in OFF position or negative battery cable is disconnected when monitoring circuit resistance. Status changes on DVOM during test procedures indicate area of fault.

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