Fuel System - MIL ON/Misfire DTC's/Stumble/Rough Idle
01-027/042000 - 2002 626 FS 4 CYL.
ROUGH IDLE/HESITATION/STUMBLE/ MISFIRE/MIL ILLUMINATION WITH DTC P0300 P0301 P0302 P0303 P0304
APPLICABLE MODEL(S)/VINS
2000 - 2002 626 with FS 4 Cyl. Engine
DESCRIPTION
Some vehicles may experience a rough idle, hesitation, stumble, and/or misfire during or immediately after a cold start. A DTC P0303 may also be stored in memory. In extreme cases, the engine may stop running and multiple misfire codes, P0300 - P0304 may be stored in memory.
Automotive fuel with high alcohol content may damage the Fuel Pressure Regulator diaphragm. The damage to the diaphragm may allow fuel to enter the vacuum supply line for the fuel pressure regulator. The vacuum supply line uses the No. 3 intake runner as the vacuum source. The un-metered fuel entering the No. 3 cylinder on cold starts may cause a rich mixture misfire.
The material of the diaphragm has been modified, and a new fuel pressure regulator has been established as a service part.
Customers having this concern should have their vehicle repaired using the following procedure.
REPAIR PROCEDURE
1. Verify the concern by inspecting the fuel pressure regulator vacuum supply hose for evidence of fuel entering the vacuum supply line.
- If no evidence of fuel or fuel smell is found, refer to Workshop Manual (section 01) for further diagnostics.
- If evidence of fuel or fuel smell is found, proceed to next step.
2. Replace the fuel pressure regulator with a new part according to the Workshop Manual (section 01 - 14 PRESSURE REGULATOR OR REMOVAL/INSTALLATION).
3. Verify the repair by allowing the vehicle to fully warm up, then allow at least a 6 hour cool down (overnight if possible) before restarting the engine.
PART(S) INFORMATION
WARRANTY INFORMATION
NOTE:
This warranty information applies only to verified customer complaints on vehicles eligible for warranty repair. Refer to the SRT microfiche for warranty term information.
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