TROUBLESHOOTING GUIDE
F-31spec tableTroubleshooting steps 6-12
6
INSPECTIONCheck for injector operating sound at idle with sound scope or screwdriver
RESULTYes
ACTIONGo to Step 8
6
INSPECTIONCheck for injector operating sound at idle with sound scope or screwdriver
RESULTNo
ACTIONGo to Step 7
7
INSPECTIONCheck if approx. 12V exists at injector connector (W/R) wire
RESULTYes
ACTIONCheck if injector resistance is OK — page F-112; Resistance: Approx. 14Ω; If OK, check wiring between ECU and injector — page F-7; If not OK, replace injector — page F-112
7
INSPECTIONCheck if approx. 12V exists at injector connector (W/R) wire
RESULTNo
ACTIONCheck wiring between ECU and injector — page F-7
8
INSPECTIONDisconnect each high-tension lead at idle and check if engine speed decreases equally each time
RESULTYes
ACTIONDisconnect each injector connector at idle and check if engine speed decreases equally each time; If OK, go to Step 10; If not OK, check injector for fuel leakage — page F-113
8
INSPECTIONDisconnect each high-tension lead at idle and check if engine speed decreases equally each time
RESULTNo
ACTIONGo to step 9
9
INSPECTIONCheck if spark plugs are OK
RESULTYes
ACTIONCheck for correct engine compression — page B-10; If OK, replace injector — page F-112; If not OK, check for cause (Refer to Section B) — page B-10
9
INSPECTIONCheck if spark plugs are OK
RESULTNo
ACTIONRepair, clear, or replace — page G-20
10
INSPECTIONCheck for correct ignition timing at idle — page F-75; Ignition timing: 10° ± 1° BTDC
RESULTYes
ACTIONCheck for correct idle speed — page F-76; Idle speed: 850 ± 50 rpm; If OK, go to next step; If not OK, adjust idle speed — page F-76
10
INSPECTIONCheck for correct ignition timing at idle — page F-75; Ignition timing: 10° ± 1° BTDC
RESULTNo
ACTIONAdjust — page F-75
11
INSPECTIONCheck for correct fuel line pressure at idle — page F-103; Fuel line pressure: 265—314 kPa (2.7—3.2 kg/cm², 38—48 psi) (Vacuum hose to pressure regulator disconnected)
RESULTYes
ACTIONGo to next step
11
INSPECTIONCheck for correct fuel line pressure at idle — page F-103; Fuel line pressure: 265—314 kPa (2.7—3.2 kg/cm², 38—48 psi) (Vacuum hose to pressure regulator disconnected)
RESULTNo
ACTIONLow pressure: Check fuel line pressure while pinching fuel return hose; If fuel line pressure quickly increases, check pressure regulator — page F-111; If fuel line pressure gradually increases, check for clogging between fuel pump and pressure regulator; If not clogged, check fuel pump maximum pressure — page F-108
12
INSPECTIONTry known good ECU and check if condition improves — page F-127
RESULT
ACTION