{"model":"mk2","model_name":"MK2 Supra","vehicle":"Toyota Supra A60 (1982–1986, 5M-GE)","document":"Repair Manual","section":"FI","section_name":"EFI System","page":18,"pages_in_section":80,"title":"Symptom — Engine BACKFIRES-Lean Fuel Mixture","section_header":"EFI System — Troubleshooting","ocr_text":"SYMPTOM — ENGINE BACKFIRES-Lean Fuel Mixture\n\nCHECK DIAGNOSIS SYSTEM\nCheck for output of diagnostic code.\n(See page FI-22)\n\nNormal code\n\nCHECK FOR VACUUM LEAKS IN AIR\nINTAKE LINE\n\nOK\n\nCHECK IGNITION TIMING\n1. Short both terminals of the\n   check connector.\n2. Check ignition timing.\n   STD: 10° BTDC\n   (w/short terminals of the\n   check connector)\n\nOK\n\nCHECK COLD START INJECTOR\n(See page FI-49)\n\nOK\n\nCHECK FUEL PRESSURE\n(See page FI-45)\n\nOK\n\nCHECK INJECTORS\n(See page FI-53)\n\nOK\n\nCHECK EFI ELECTRONIC CIRCUIT\nUSING VOLT/OHMMETER\n\nMalfunction\ncode(s)\n\nBAD\n\nBAD\n\nBAD\n\nBAD\n\nBAD\n\nBAD\n\nDiagnostic code(s)\n(See page FI-22)\n\n1. Oil filler cap\n2. Oil level gauge\n3. Hose connections\n4. PCV hoses\n5. EGR system — EGR valve stays open\n\nIgnition system (See page IG-2)\n\n1. Cold start injector\n2. Start injector time switch\n   (See page FI-71)\n\n1. Fuel pump (See page FI-44)\n2. Fuel filter\n3. Fuel pressure regulator (See page FI-52)\n\nInjectors — clogged\n\n1. Wiring connection\n2. Power to ECU\n   (1) Fusible link\n   (2) No.1 and No. 2 main relay\n3. Air flow meter\n4. Water temp. sensor\n5. Air temp. sensor\n6. Throttle position sensor\n7. Injection signal circuit\n   (1) Injection wirings\n   (2) Resistor\n   (3) ECU\n   (4) Fuel cut signal\n8. Oxygen 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transcript of a scanned Toyota factory manual page; verify critical values (torque specs, part numbers) against the image."}