Fuel Rail - Hard Engine Start/Rough Idle/Miss
NO: 18-02-94GROUP: Driveability
DATE: Jan. 21, 1994
SUBJECT:
Hard Start, Long Crank Time, Engine Miss
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 18-15-93 DATED NOV. 30, 1993 WHICH SHOULD BE REMOVED FROM YOUR FILES. A NOTE HAS BEEN ADDED IN THE REPAIR PROCEDURE REFERENCING TECHNICAL SERVICE BULLETIN 14-16-93, DATED OCT. 22, 1993, "FUEL PRESSURE REGULATOR INSTALLATION". ALL REVISIONS ARE HIGHLIGHTED WITH ** ASTERISKS**.
MODELS:
1993 - 1994 (LH) Concorde/Intrepid/Vision/LHS/New Yorker
NOTE:
THIS BULLETIN APPLIES TO VEHICLES WITH A 3.5L ENGINE.
SYMPTOM/CONDITION:
Any one or more of the following customer complaints: Long crank time or hard starting, rough engine idle, or engine miss at idle. No fault codes generated.
DIAGNOSIS:
Begin diagnosis by using the DRB II Scan Tool to monitor left and right cylinder bank adaptive memory. This is done by getting the vehicle to a warm idle in "Park" and selecting the following from the "SELECT SYSTEM" menu:
ENGINE FUEL/IGNITION MONITORS ADAPTIVE MEMORY
At the bottom of this Adaptive Memory Monitor Screen, left and right 02 sensor adaptive values are shown. Normal adaptive values will read between +5 and -5. If the left bank adaptive value reads between -6 and -20, replace the fuel rail assembly.
Additional diagnosis can be performed by pulling the # 2 spark plug to inspect for fouling. In addition, fuel pressure can be checked at the fuel rail (via the fuel pressure test port) for a slow loss of pressure after the engine is shut off. The procedure for checking the fuel system pressure is outlined in Section 14 of the Service Manual, test NTC 3A of the Powertrain Diagnostic Manual, and the Mopar Diagnostic System under "No Diagnostic Trouble Code Diagnostics".
NOTE:
DO NOT REPLACE THE FUEL RAIL ASSEMBLY UNLESS ONE OR MORE OF THESE DIAGNOSTIC PROCEDURES INDICATES A PROBLEM. REPLACING THE FUEL RAIL ASSEMBLY FOR OTHER THAN THE SPECIFIC DIAGNOSTIC RESULTS INDICATED IN THIS BULLETIN WILL NOT IMPROVE IDLE QUALITY.
PARTS REQUIRED:
REPAIR PROCEDURE:
This bulletin involves replacing the fuel rail assembly.
Replace the fuel rail assembly as described on Page 14-70 of the 1994 Concorde/Intrepid/Vision/LHS/New Yorker Service Manual (Publication No. 81-270-4140).
** NOTE:
IF THE FUEL PRESSURE REGULATOR AND O-RINGS ARE NOT PROPERLY TRANSFERRED TO THE NEW FUEL RAIL A LOSS OF FUEL PRESSURE WILL RESULT. WHEN REMOVING THE FUEL PRESSURE REGULATOR, THE O-RINGS MAY REMAIN ATTACHED TO THE REGULATOR. THEY MUST BE REMOVED FROM THE REGULATOR AND SEPARATELY INSTALLED INTO THE FUEL RAIL CAVITY. WHEN INSTALLING O-RINGS, APPLY A LIGHT COAT OF CLEAN ENGINE OIL AND SEAT THEM INTO THE CAVITY BEFORE INSERTING THE REGULATOR.**
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE
Labor Operation No. 14-70-14-92 1.5 Hrs.
FAILURE CODE: 59 - Internal Leak