PROM - Hesitation, Sag, Stall When Cold

File In Section: 6E - Engine Fuel & Emission

Bulletin No.: 77-65-25A

Date: March, 1998

Subject:
Hesitation, Sag, or Engine Stall During Cold Driveaway Maneuver (Reprogram PCM)

Models:
1998 Chevrolet Cavalier
1998 Pontiac Sunfire
with 2.2L Engine (VIN 4 - RPO LN2) and Automatic Transmission (MD9, MN4)





Vehicles Involved:
Involved are Certain 1998 J-Car Models Equipped with the 2.2L (RPO LN2) VIN Engine Code 4 Engine, that Fall within the VIN Breakpoints:

This bulletin is being revised to update calibration information. Please discard Corporate Bulletin Number 77-5-25 (Section 6E - Engine Fuel & Emission).

Condition

Some vehicles may exhibit a hesitation, engine sag, or an engine stall during light acceleration (30 percent throttle or less) when the engine is cold. This condition may be more noticeable when the ambient temperature is less than 10°C (50°F).

Cause

Certain fuels in combination with variations in manufacturing may allow some cars to run leaner under certain conditions.

Correction

Reprogram the PCM with the revised calibration that takes into account the above conditions. These calibrations are available on 1997 CD-ROM # 19 and later versions.





Calibration Numbers

Use the correct calibration from the list as shown.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation Description Labor Time

J6355 Reprogram PCM 0.4 hr
(on car)
J6352 Reprogram PCM 0.4 hr
(off car)