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Properly relieve the fuel system pressure and install a pressure test gauge according to the tool manufacturers instructions.
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Turn the ignition switch to the ON position for 3 seconds, then turn to the OFF position for 5 seconds. Repeat this procedure two or three times to pressurize the system. Again turn the switch to the ON position.
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On TBI equipped vehicles, the gauge should read a static pressure of between 9 and 13 psi (62-89kPa)
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On SFI equipped vehicles, the gauge should read a static pressure of between 41 and 47 psi (248-325kPa)
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If not, check for a clogged fuel filter, a kinked fuel line, or an inoperative fuel pump.
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On TBI equipped vehicles, the fuel pressure will drop after the fuel pump stops running due to a controlled bleed in the fuel system. Use of the fuel pressure gauge will determine if the fuel system pressure is enough for the engine to start and run.
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No fuel spray from the injector indicates a faulty fuel or ignition system or no PCM control of the injector.
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This test will determine if the ignition control module is not generating the reference pulse or if the wiring or PCM are at fault. By touching and removing a test light to B+ on CKT 430 (purple/white wire from the ignition system), a reference pulse should be generated. If the injector test light blinks, the PCM and wiring are OK.
If the pump tests bad...
Disconnect the negative battery cable.
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Relieve the fuel system pressure.
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Block the front wheels and raise and support the rear of the vehicle safely. Make sure the rear is high enough to accommodate the removal of the fuel cell.
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Loosen the fuel filler neck connecting tube clamp at the tank.
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Wrap a shop towel around the fuel filter neck connecting tube and slowly remove the fuel filler neck connecting tube from the fuel tank.
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Position a siphon hose into the fuel tank through the fuel filler opening. Place the other end into an approved container with enough capacity to hold the fuel in the tank. Siphon the fuel.
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Raise the vehicle to gain access to the fuel tank. Make sure the vehicle is safely supported.
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Disconnect the tail pipe hanger attaching bolt.
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Remove the muffler hanger attaching bolts and remove the muffler hanger.
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Loosen the converter hanger attaching nuts.
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Remove the two heat shield attaching screws and note the position for reassembly.
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Support the exhaust and move the heat shield to gain the access to the right side of the fuel tank retaining strap attaching bolts.
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Remove the in-line fuel filter body clips.
If the nylon fuel feed or return lines becomes kinked, and cannot be straightened, they must be replaced. Do not attempt to repair sections of the nylon fuel lines.
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Disconnect the quick-connect fitting at the fuel filter, and return line fitting.
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Disconnect the fuel tank electrical connector.
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Disconnect the vapor hose at the fuel tank.
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Disconnect the vent hose at the fuel tank.
With the aid of an assistant, support the fuel tank, remove the left and right tank retaining strap attaching bolts, and remove the tank.
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As necessary, remove the fuel sending unit (which includes the fuel pump), as outlined, in this section.
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Then you can change the pump:
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Remove the fuel sender assembly.
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Disassemble the fuel pump strainer and the fuel pump: Note the position of the strainer in relation to the pump.
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See Figure 3
Fig. 3: Remove the fuel tank locking ring with a non-sparking (brass) punch.
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Support the fuel pump in one hand, and grab the strainer in the other hand.
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Rotate strainer in one direction and pull off pump. Discard strainer.
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Remove deflector.
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Disconnect the fuel pump electrical connector.
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Loosen the two connecting clamps, if equipped.
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Place the fuel sender assembly upside down on the work bench.
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Pull the fuel pump downward to remove it from the mounting bracket, then tilt the pump outward and remove it from the connecting hose or the fuel pulse dampener.
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It is recommended to replace the hose and clamps, if equipped.
To install:
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Push the fuel pump assembly into the attaching hose. Attach the pump electrical wires and fasten the hose clamps to the attaching hose and around the pump body, where equipped.
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Place the fuel tank sender and pump assembly into the fuel tank. Use a new O-ring seal during assembly.
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Then put the tank back in:
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If the fuel tank is replaced, transfer the fuel feed and return lines from the mounting clips, the vapor hose from the mounting clips and the vent hose from the vent hose fitting.
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Check the fuel filler neck for cracks and holes and replace as necessary.
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Install the fuel sending unit.
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With the aid of an assistant, position and support the fuel tank and install the left and right tank retaining strap attaching bolts and tighten to 18 ft. lbs.
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Connect the vent and vapor hoses.
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Connect the fuel sending unit electrical connector.
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Connect the quick-connect fittings as outlined.
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Position the fuel sending unit electrical connector and fuel return line under the in-line fuel filter bracket.
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Install the in-line fuel filter and new body clips.
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Reposition the heat shield as noted during removal and tighten the retaining screws to 18 lbs. ft.
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Tighten the converter hanger attaching bolts to 20 lbs. ft.
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Install the muffler hanger and attaching bolts and tighten to 18 lbs. ft.
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Install the tailpipe hanger attaching bolt and tighten to 20 lbs. ft.
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Lower the vehicle, add fuel and install the fuel filler cap.
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Connect the negative battery cable.
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Turn the ignition switch to the ON position for 3 seconds, then turn to the OFF position for 5 seconds. Repeat this procedure two or three times to pressurize the system. Again turn the switch to the ON position and check for leaks.
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