Buzzing Around in a Ford Mustang
By Eric Seifert. ALLDATAAlex picked up a used 1998 Mustang from a private seller a few weeks ago. When he took the test drive, he mentioned to the seller that he heard a buzzing noise whenever the radio was on. The seller said that the car had "always made that noise." After Alex bought the car, he drove it straight over to us. We recently had run across a similar issue with an F250, so the diagnosis was pretty quick. A "whining" or "buzzing" noise in the speakers of the entertainment radio or a two-way radio may be caused by in-tank fuel pump electrical noise. Fuel pump radio noise is relatively constant and changes only slightly with vehicle speed. If the frequency of the noise varies or the noise comes and goes with vehicle speed, then it is not the pump. Test Procedure: 1. Turn on the radio before the key is turned on. 2. Turn the ignition key to the Run position (do not start the engine). 3. The fuel pump should run for about one second with the key in the Run position with the engine not running. Listen for noise in the radio. If noise is present while the pump is running and stops when the pump stops, then the noise is being generated by the pump.Solution: 1. Install a electronic noise Radio Frequency Interference (RFI) Filter on the fuel pump. 2. Only a few parts will be required: a F1PZ-18B925-A Radio Frequency Interference (RFI) Filter (1 per each in-tank pump), 95873-S101 Bundling Strap and some F5AZ-14A099-AA Heat Shrink Tubing. (NOTE: If the vehicle has an electronic returnless fuel system, do not install an RFI filter. ) 3. Applicable vehicles, all of which are registered trademark names and model designations of Ford Motor Company, include : 90-94 Tempo, Topaz, 90-97 Escort, Tracer, Probe, Thunderbird, Cougar, Aerostar, 90-98 Mustang, 90-99 Taurus (Except Flex Fuel), Sable, 01 Taurus, Sable, 90-02 Crown Victoria, Grand Marquis, Town Car, 97-99 Contour, Mystique, 90 Bronco II, 90-96 Bronco, 90-97 F Super Duty, F-250 HD, F-350, 90-99 F-250 LD, 90-02 Econoline, F-150, Ranger (Except 1999 3.0L Flex Fuel) 91-02 Explorer, Mountaineer, 95-02 Windstar, 97-03 Expedition, Navigator, 99-02 Super Duty F Series, 00-02 Excursion, Explorer Sport Trac, Explorer Sport, 01-02 Escape, 90-92 Mark VII, 90-94 Continental, 02 Blackwood and 93-02 Villager.Repair Procedure:
Review Fuel Tank/Pump Service and Repair including safety procedures in the ALLDATA(r) system before beginning. Note that heat shrink tubing must be used over all soldered connections. Use sufficient tubing to cover each connection and prevent exposure. (WARNING: All soldering and heat shrinking must be completed away from the fuel tank area.) 1. Remove the fuel pump sender assembly from the tank.
2. On vehicles without a fuel delivery module, remove the negative and positive connectors from the fuel pump, as per Figure
1.
i. Cut the wires to the fuel pump 76 mm (3") from the flange of the pump and
discard.
ii. Connect the RFI filter connectors to the spade terminal on the pump.
iii. Cut and solder both the red and black wires of the filter to the red and black wires of the flange. Use Heat Shrink Tubing over the solder connections.
3. On trucks with a fuel delivery module, cut the fuel pump wires to the module 50 mm (2") from the flange and discard, Figure
2.
i. Cut the connectors from the RFI filter and solder wires to the module (red to red and black to black). Use heat shrink tubing over solder
connections.
ii. Solder wires from the filter to the flange (red to red and black to black). Use heat shrink tubing over soldered
connections.
4. Secure the RFI filter to the fuel pump and sender assembly with a Bundling Strap to prevent rattling in the tank, Figures 1 and
2.
5. Reinstall the fuel pump sender assembly into the tank.CAUTION: Install new gaskets when reinstalling sender to prevent
leaks.
6. Check ALLDATA for location of the fuel pump ground. If ground is more than 0.9m (3') from the tank, cut wire and ground fuel pump end within 0.9m (3') of the tank to prevent the ground wire from acting as an antenna. Be sure ground is secure and protected from corrosion since it is the operating ground for the fuel
pump.
7. Install the fuel tank in the vehicle.
(Source: ALLDATA LLC)
