{"model":"mk2","model_name":"MK2 Supra","vehicle":"Toyota Supra A60 (1982–1986, 5M-GE)","document":"Repair Manual","section":"EM","section_name":"Engine Mechanical","page":5,"pages_in_section":64,"title":"Idle HC/CO Concentration","section_header":"Engine Mechanical — Idle HC/CO Concentration","ocr_text":"NOTE: This check method is used only to determine whether or not the idle HC/CO complies with regulations.\n\nPRECHECK\n\nINITIAL CONDITIONS\n(a) Air cleaner installed\n(b) Normal engine operating temperature\n(c) All pipes and hoses of air intake system connected\n(d) All accessories switched off\n(e) All vacuum lines properly connected\nNOTE: All vacuum hoses for EGR systems, etc. should be properly connected.\n(f) EFI system wiring connectors fully plugged\n(g) Ignition timing set correctly\n(h) Transmission in N range\n(i) Tachometer and HC/CO meter calibrated and at hand\n\nMEASUREMENT\n\n1. RACE ENGINE AT 2,500 RPM FOR ABOUT 2 MINUTES\n\n2. INSERT TESTING PROBE OF HC/CO METER INTO TAILPIPE AT LEAST 40 cm (1.3 ft)\n\n3. MEASURE HC/CO CONCENTRATION AT IDLE\nWait at least one minute before measuring to allow the concentration to stabilize.\nComplete the measuring within three minutes.\nIf the HC/CO concentration does not conform to your regulations, see the table below for possible causes.\n\nTROUBLESHOOTING\n\nHC | CO | Symptoms | Causes\nHigh | Normal | Rough idle | 1. Faulty ignition:\n• Incorrect timing\n• Fouled, shorted or improperly gapped plugs\n• Open or crossed ignition wires\n• Cracked distributor cap\n2. Faulty EGR system:\n• EGR valve\n3. Leaky exhaust valves\n4. Leaky cylinder\n\nHigh | Low | Rough idle\nFluctuating\nHC reading | 1. Vacuum leak:\n• Vacuum hose\n• Intake manifold\n2. Lean mixture causing misfire\n\nHigh | High | Rough idle\nBlack smoke\nfrom exhaust | 1. Restricted air filter\n2. Faulty EFI system:\n• Faulty pressure regulator\n• Clogged fuel return line\n• Faulty air flow meter\n• Defective water temp. sensor\n• Defective air temp. sensor\n• Faulty ECU\n• Faulty injector\n• Faulty cold start injector\n• Faulty throttle position sensor","image":"https://tsrm.sasquatchvc.com/images/mk2/EM/EM_005.png","url":"https://tsrm.sasquatchvc.com/mk2/tsrm/EM/5","prev":{"page":4,"url":"https://tsrm.sasquatchvc.com/mk2/tsrm/EM/4","api":"https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/4"},"next":{"page":6,"url":"https://tsrm.sasquatchvc.com/mk2/tsrm/EM/6","api":"https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/6"},"section_url":"https://tsrm.sasquatchvc.com/mk2/tsrm/EM","section_api_pages":["https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/1","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/2","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/3","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/4","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/5","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/6","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/7","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/8","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/9","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/10","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/11","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/12","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/13","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/14","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/15","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/16","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/17","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/18","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/19","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/20","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/21","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/22","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/23","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/24","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/25","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/26","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/27","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/28","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/29","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/30","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/31","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/32","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/33","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/34","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/35","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/36","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/37","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/38","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/39","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/40","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/41","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/42","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/43","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/44","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/45","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/46","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/47","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/48","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/49","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/50","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/51","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/52","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/53","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/54","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/55","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/56","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/57","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/58","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/59","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/60","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/61","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/62","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/63","https://tsrm.sasquatchvc.com/api/pages/mk2/tsrm/EM/64"],"note":"OCR transcript of a scanned Toyota factory manual page; verify critical values (torque specs, part numbers) against the image."}