Fuel - Sag, Hesitation, or No Start In Hot Weather

91chevy04

Number: 89-241-6E


Section: 6E


Date: August 1989


Corporate Bulletin No.: 936520


Subject: HOT WEATHER DRIVEABILITY


Model and Year: 1989 B CAR WITH 4.3L, 5.0L, AND 5.7L ENGINES


TO: ALL CHEVROLET DEALERS


Some 1989 4.3L, 5.0L, and 5.7L Throttle Body Injected (TBI) B-cars may exhibit hot weather driveability conditions. They may be in the form of a sag, hesitation, and/or no start and usually occur after an extended idle and/or hot soak. Vehicles exhibiting these conditions may be repaired by installing parts and following the procedure indicated below.

PART: PART NUMBER:

Fuel pump inlet strainer/sock 25121401

Diffuser disc 25027515

O-ring 3893116

Relief valve 17089068

Parts are currently available from GMSPO.





Installation Procedures:

1. Disconnect Battery

2. Remove existing tank pressure control valve underhood and discard.

3. Install new tank pressure control valve (underhood) as shown in illustration 1.


4. Remove fuel tank pump and sender assembly following applicable shop manual procedure.

5. Remove existing fuel pump strainer/sock and discard.


IMPORTANT: Inspect fuel sender assembly to ensure the installation of either the production spacer or the service correction (consisting of a washer and clamp) on the sender feed pipe that retains the hose coupler in correct location.

Reference Dealer Service Bulletin No. 89-126-6C.








6. Install diffuser disc over pump inlet, position and install new strainer/sock as shown in illustration 2, and illustration 3.


7. Utilizing new sender O-ring, install sender and tank assembly following applicable shop manual procedure.

8. Reconnect the battery.

9. Start vehicle, inspect for fuel leakage and correct as required.

Labor Operation Number: J5590

Labor Time: 1.2 Hours