FUEL PUMP NOISE ON COUPES & SEDANS WITH V-6 ENGINE

VEHICLES AFFECTED: 1985-87 'A' CAR COUPES AND SEDANS WITH V-6 ENGINES (VIN CODE W) 1987 H (VIN CODE 3)

Some 1985-87 'A' car sedans and coupes with V-6 engines (LB6) and 'H' car (LG3) may exhibit what is considered to be an objectionable level of fuel pump noise audibile in the vehicle passenger compartment.

This level of noise may be attributed to any of the components or conditions listed below:

1. Fuel Pump 2. Pulsator 3. Inadequate pump discharge port to sender feed pipe clearance. 4. Improper tank to underbody position/isolation resulting in ground out.

Vehicles exhibiting this condition may be repaired by following the procedure below:

1. Drain and lower fuel tank following applicable shop manual procedure in Section 6C.

2. Remove existing anti-squeak material from tank and discard.

3. Clean top of fuel tank and remove fuel sender/pump assembly.

4. Check for a loose tank baffle by pressing on the baffle after the pump is removed. If looseness is felt, replace the tank.

5. Remove and discard pulsator. Inspect to insure a minimum distance of 1/4 inch exists between pump discharge port and sender feed pipe, (See Figure 1). Replace sender as required.

6. Inspect pump under foam isolation sleeve for part number. If part number is either 6442409 or 6442439, replace the pump.

7. Reassemble sender/pump assembly utilizing new pulsator, P/N 25094266, insuring pump and pulsator are positioned properly (Figures 1 and 2).

8. Install pump and sender in tank without the sealing "O" ring. If the sender cover does not rest on the "O" ring seat, the pump is bottoming out on the tank bottom, in which case it will be necessary to obtain clearance.

9. Remove the sender assembly and reinstall using new sender sealing "O" ring or gasket.

10. Using the insulator pieces, apply to the tank as shown in Figures 3 and 4.

11. Position and secure the fuel lines so that they do not touch.

12. Raise and position fuel tank to vehicle underbody. Loosely attach straps to underbody placing two 7/16" flat washers, P/N 3899696, or equivalent on each of the strap bolts between strap and under-body attaching point (Figure 5).

13. Insure fuel tank strap spacer located on L.H. strap is properly positioned under forward flange of tank (Figure 6). Torque L.H. strap bolt and then R.H. bolt to 25 ft. lbs (34 Nm).

14. Inspect to insure forward tank flange is not contacting strap body bracket, and that sender pipes are not in contact with either tank or underbody. Correct as required.

15. Reconnect fuel hoses and electrical connector following service manual procedure.

16. Start vehicle, inspect for any fuel leakage and repair as necessary.

Parts required for this procedure are available from GM Parts and are noted below with the exception of the pump and sender part numbers, which are found in the GM Parts Catalog.

Application Part Number Description Quantity Required

"A" Car 22508205 Insulator 1 "H" Car 22530172 Insulator 1 and 22530290 Insulator 1

"A" and "H" Cars 25094266 Pulsator 1

"A" and "H" Cars 3899696 7/16" Flat Washer Or 4 Equivalent

"H" Car 22515965 Fuel Sending 0-ring 1

"A" Car 3893116 Fuel Sending Gasket 1

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.