Fuel Pump - Noise

Article No. 85-11 -12

NOISE - ELECTRIC FUEL PUMP - TWO PUMP SYSTEM

FORD 1984-85 LTD, 1983-84 THUNDERBIRD, MUSTANG

LINCOLN-MERCURY 1984-85 MARQUIS, 1983-84 CONTINENTAL, MARK, COUGAR, CAPRI

CALIBRATIONS: ALL WITH EEC IV

WARNING: This modification is authorized only for the listed engines. Performing this modification on other engine calibrations is unauthorized and could create liability under applicable federal or local laws.

The subject vehicles have a low pressure in-tank fuel pump and an external high pressure fuel pump. A noise damper is located in the inlet of the high pressure pump to prevent oscillation and noise. A noise will be heard coming from the fuel tank if this damper is missing or fails. When this occurs, the low pressure pump is sometimes falsely diagnosed as being the source of the noise.
The following procedure should be followed if the low pressure fuel pump is suspected of causing noise:

1. Test the low pressure fuel pump for function as outlined in Section 24-35 of the Shop Manual.

2. If the pump performs satisfactorily, check the vibration level of the fuel lines at the high pressure pump inlet and outlet. If there appears to be a large difference between the inlet and outlet vibration, change the high pressure fuel pump and retest for noise.

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.

OPERATION: Test (Step 1) SP9350B
TIME: 0.4 Hr.
OPERATION: Change Pump (Step 2) SP9350A
TIME: 0.6 Hr.

DLR. CODING: Basic Part No. 9350 - Code: P8