Fuel Pump - Noise
88pontiac07Number Date
87-6(Gasoline)-89 5/88
Subject: FUEL PUMP NOISE
1985-87 FIREBIRD MODELS WITH V-6 (VIN CODE S, F, 8)
(RPO LB8) AND V-8 (RPO LB9, L98) ENGINES
Some 1985-87 Firebird models with V-6 (RPO LB8) or V-8 (RPO LB9, L98) engines may exhibit increased noise generated by the intank fuel pump that is audible in the vehicle passenger compartment.
This condition may be attributed to any of the components or conditions noted 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 procedures.
2. Remove existing anti-squeak material from tank, tank straps, and vehicle underbody and discard.
3. Clean tank straps and tank top with suitable solvent and remove fuel sender/pump assembly.
Figure 1:
4. Remove and discard pulsator. Inspect to insure minimum distance of 1/4 inch exists between pump discharge port and sender feed pipe (see Figure 1). If minimum distance does not exist, replace sender as required (see GMSPO part catalog for correct application).
5. Remove and discard fuel pump and replace with applicable fuel pump noted on Page 4 of this bulletin by engine type.
6. Reassemble sender/pump assembly utilizing new pulsator, P/N 25094266, insuring pump, pulsator and strainer are positioned properly (see Figure 1).
Figure 2:
7. Position isolation material contained in sound isolation kit, P/N 10093234, to tank top and tank straps (see Figure 2).
Figure 3:
8. Install sender/pump assembly into fuel tank utilizing new fuel sender O-ring.
9. Position and secure sender pipe spacer/isolator with tie strap to prevent pipes from becoming dislodged (see Figure 3).
10. Install tank to vehicle underbody ensuring it is positioned so that tank sits freely in underbody guides. Secure in position torquing strap bolts/screws to 25 ft.lbs.
11. Complete reassembly of vehicle following shop manual procedures.
12. Start vehicle, inspect for any fuel leakage and repair as necessary.
Parts that are required for this procedure are available from GMSPO and are noted below excluding applicable sender part numbers which can be procured from GMSPO Parts Catalog.
Part Number Description Quantity Required
10093234 Sound Isolation Kit 1
25094266 Pulsator 1
25116162 Fuel Pump (LB8) 1
25116163 Fuel Pump (LB9/L98) 1
Use applicable labor operation number and time.