626 LX L4-2.0L DOHC (1999)
Intake Manifold Gasket: Customer Interest
Engine - Rough Idle/Hesitation on Acceleration/MIL ON
Bulletin No.: 015/00
Issued: 10/18/00
Revised:
Section:
01
APPLICABLE MODEL(S)/VINs
All 1998-01 4-cylinder 626 with VINs lower than 1YV GF22C4 15202676.
DESCRIPTION
The MIL may illuminate with DTCs P0171 or P0301-P0304 stored in memory. There may also be a concern of rough idle or hesitation on acceleration.
These concerns can be caused by a vacuum leak at the intake manifold gasket.
Customers having this concern should have their vehicle repaired using the following procedure.
REPAIR PROCEDURE
1.
Verify customer concern.
2.
Using the NGS Tester, retrieve any DTCs stored and record Freeze Frame Data.
3.
Start the engine and select the Short Fuel Trim PID (SHRTFT1) and Long Fuel Trim PID (LONGFT1).
Note
^
High positive values (e.g. +12% or greater) for SHRTFT1 or LONGFT1 stored in Freeze Frame Data or seen in PID data may indicate that
unmetered air is entering the engine through a vacuum leak at the intake manifold gasket.
4.
Using an aerosol spray such as carburetor cleaner, spray around the intake manifold gasket while watching for changes in idle speed or SHRTFT1
values.
Note
^
Be sure to spray the gasket area under intake runners # 1 and # 4 cylinders.
-
If changes in idle speed or SHRTFT1 indicate a potential vacuum leak, replace the intake manifold gasket according to the Workshop Manual
(01-13A Intake-Air System Removal/Installation [FS]).
-
If no changes in idle speed or SHRTFT1 are seen, continue diagnosing according to the Workshop Manual (01-01A TROUBLESHOOTING
[ENGINE CONTROL FS]).
5.
Verify repair.
PART(S) INFORMATION
WARRANTY INFORMATION
