Summit L4-1468cc 1.5L SOHC (1989)
Air Flow Meter/Sensor: All Technical Service Bulletins
Valve Cover - Engine Hesitation/Surge/Stumble
NO.: 18-57-91
GROUP:
DRIVEABILITY
DATE:
Nov. 18, 1991
THIS BULLETIN SUPERSEDES TECHNICAL SERVICE BULLETIN 18-55-90 WHICH SHOULD BE REMOVED FROM YOUR FILES. THE
REVISIONS ARE HIGHLIGHTED IN RED AND >>ARROWS<<.
MODELS:
1989-90 (B2) SUMMIT
>>SYMPTOM/CONDITION:<<
Vehicles equipped with a 1.5L engine and an automatic transaxle, may exhibit a hesitation, surge, stumble, or driveway dieout within the first 60 seconds
after a cold start. Vehicles equipped with a manual transaxle may exhibit a surge condition, with engine at full operating temperature, while driving at a
steady speed.
NOTE:
VEHICLES EQUIPPED WITH AN AUTOMATIC TRANSAXLE EXHIBITING A SURGE AT 45-55 MPH SHOULD HAVE
TECHNICAL SERVICE BULLETIN 18-19-90 PERFORMED.
DIAGNOSIS:
Verify the vehicle is functioning as designed using the DRB II, and the appropriate Diagnostic Test Procedure. If no problems are found, perform the
repair procedure.
PARTS REQUIRED:
1
Cylinder Head Cover
MD168907
REPAIR PROCEDURE:
This repair involves cleaning several engine components of oil and carbon deposits, and the installation of a new style valve cover.
Figure 1
1.
Confirm the air flow sensor identification number (E5TO1571) as marked on the side of the air flow sensor (Figure 1). Inspect the air passage of
the sensor and verify that one of the air by-pass holes are plugged. If both of the by-pass holes are open, the air flow sensor must be replaced using
the correct sensor, PN MD118125.
2.
As outlined in the appropriate service manual, remove the throttle body, air intake hose, intake plenum and intake manifold.
