|
|
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS TSB Revision MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE> 13B-773 INSPECTION PROCEDURE 7: Unstable Idle (rough idle, hunting). . COMMENT • In cases such as the above, the cause is proba- bly the air/fuel mixture. Other systems affecting . TROUBLESHOOTING HINTS (The most • Malfunction of the fuel pump system. • Malfunction of the ignition system. • Malfunction of the injector system. • Poor compression • Malfunction of the purge control system • Malfunction of the EGR system • Improper operation of the PCV valve. • Malfunction of the charging system. • Vacuum leak. • Contaminated fuel. • Malfunction of the ECM. DIAGNOSIS Required Special Tools: • MB991958: Scan Tool (M.U.T.-III Sub Assembly) • MB991824: V.C.I. • MB991827: USB Cable • MB991910: Main Harness A • MB992110: Power Plant ECU Check Harness STEP 1. Check if the EGR valve sounds during YES : Go to Step 2. − Exhaust Gas Recirculation (EGR) System − EGR Valve (Stepper Motor) Check STEP 2. Using scan tool MB991958, read the diagnostic CAUTION To prevent damage to scan tool MB991958, always turn the YES : Refer to Diagnostic Trouble Code Chart . NO : Go to Step 3. AK700568AB MB991824 MB991827 MB991910 Data link |