2.
Was a problem found in any of the above areas?
YES
▶ Replace or repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
▶ Go to "Engine oil contamination Inspection" procedure.
Visually/physically inspect the following items:
-Air cleaner filter element for excessive dirt or for any foreign objects.
-Throttle body inlet for damage or for any foreign objects.
-Throttle bore, throttle plate and the IAC passages for chocking and for any foreign objects.
-Restricted exhaust system.
Was a problem found in any of the above areas?
YES
▶ Replace or repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
▶ Go to "Engine oil contamination Inspection" procedure.
Check the engine oil level. The oil level should be between the min. and max. marking. Fill to the correct oil level.
Warm up the engine to normal operating temperature.
Install Scantool and note the "S/TERM FUEL TRIM(B1)" parameter on the Scantool data list.
Disconnect and plug the positive crankcase ventilation
Monitor the "S/TERM FUEL TRIM(B1)" parameter on the Scantool data list once again.
Specification : The value should remain more or less unchanged.
Is the displayed value within the specified value?
YES
▶ Go to "Sensor Contamination Inspection" procedure.
NO
▶ The engine oil is diluted with fuel. Chang the oil and oil filter and go to "Verification of Vehicle Repair" procedure.
Visually/physically inspect following items:
-Remove and inspect the HO2S(B1S1) for any silicon contamination. This contamination will be indicated by a white powdery coating and this will result in a but false voltage signal.
-Check MAFS for contamination, deterioration, or damage.
-If contamination is evident on the HO2S or MAFS, replace contaminated sensor and go to next step.
Check the EVAP. EM system for possible over.
Remove the manifold side vacuum hose from the EVAP canister purge valve.
Using a hand vacuum pump apply specified vacuum(Approx. 15 in, Hg) to the manifold side of the valve.
Does the valve hold vacuum?
YES
▶ Go to "Fuel System Inspection" procedure.
NO
▶ Repair air leakage and go to "Verification of Vehicle Repair" procedure.
Check the fuel for excessive water, alcohol, or other contaminants. Replace contaminated fuel as necessary.
Install a fuel pressure gage.
Inspect fuel pressure with engine idling at normal operating temperature.
Specification : 338~348kPa(3.45~3.55kg/㎠)
Is fuel pressure within the specified value?
YES
▶ Go to "Fuel Injector Inspection" procedure as below
NO
▶ Repair as necessary refer to inspection note as below and go to "Verification of Vehicle Repair" procedure.
A) Check if fuel line pressure decreases when accelerating quickly.
-If it does, check fuel pump maximum pressure. If pressure is OK, check fuel line and filter for clogging.
B) If fuel pressure is lower than specification : Check for fuel line pressure while pinching fuel return hose.
-If pressure quickly increases, check pressure regulator.
-If pressure gradually increases, check for clogging between fuel pump and pressure regulator. If hose is not clogged, check fuel pump maximum pressure
C) If fuel pressure is higher than specification : Is fuel line clogged?
-If it is not, replace pressure regulator.
-If it is, replace it.
Check the fuel injectors for clogging or any restrictions.
Test Condition : Ignition "OFF".Specification : No clogging and restriction.
Is the fuel injector OK?
YES
▶ Visually/physically inspect the engine mechanical problem. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
▶ Check injector for contamination, deterioration, or damage. Substitute with a known-good injector and check for proper operation. If the problem is corrected, replace injector and then go to "Verification of Vehicle Repair" procedure.
