Fuel pump relay

If your fuel pump is working but not delivering fuel to the engine, it could be due to a few different reasons. Here are some possible causes and troubleshooting steps to take:

1. Clogged fuel filter: A clogged fuel filter can restrict the flow of fuel to the engine. Try replacing the fuel filter and see if that solves the problem.
2. Fuel pressure regulator malfunction: The fuel pressure regulator regulates the pressure of fuel delivered to the engine. If it's malfunctioning, it may not be delivering enough fuel to the engine. A mechanic can check the fuel pressure regulator and replace it if necessary.
3. Faulty fuel pump relay: The fuel pump relay is responsible for turning on the fuel pump when the engine starts. If the relay is faulty, it may not be sending power to the fuel pump, even though the pump is working. You can check the relay by swapping it with a known good relay of the same type.
4. Clogged fuel lines: Fuel lines can become clogged with dirt or debris, which can restrict the flow of fuel to the engine. A mechanic can inspect the fuel lines and clean or replace them if necessary.
5. Bad fuel pump: Even though the fuel pump is running, it may not be delivering enough fuel to the engine due to a malfunction. A mechanic can test the fuel pump to determine if it's functioning properly and replace it if necessary.

In any case, if you're having trouble getting fuel to the engine, it's best to have a qualified mechanic diagnose and fix the problem.

Your vehicle has no fuel pump relay . Has a fuel pump flow control module .
Fuel Pump Flow Control Module (FPCM)
The fuel pump flow control module (FPCM) is a serviceable GMLAN module. The FPCM receives the desired fuel pressure message from the engine control module (ECM) and controls the fuel pump located within the fuel tank to achieve the desired fuel pressure. The FPCM sends a PWM signal to the fuel pump, and pump speed is changed by varying the duty cycle of this signal.
Plus it has two fuel pumps !
The high pressure fuel pump (9) is a mechanical one cylinder design driven by an eccentric on the exhaust camshaft (1) of bank 2. High pressure fuel is regulated by the fuel rail pressure (FRP) regulator, which is a part of the high pressure fuel pump. The FRP regulator is a magnetic actuator which controls the inlet valve of the high pressure pump. The ECM provides battery voltage on the actuator high circuit and ground on the actuator low reference circuit. Both circuits are controlled by the ECM. When the ECM deactivates the FRP regulator, both circuits are disabled and the inlet valve is held open with spring pressure. When the ECM activates the FRP regulator, the low circuit driver connects the low reference circuit to ground and the high circuit driver pulse-width modulates (PWM) the high circuit. The ECM uses the camshaft and crankshaft position sensor inputs to synchronize the FRP regulator with the position of the eccentric on the camshaft. The ECM regulates fuel pressure by adjusting the portion of each pump stroke that provides fuel to the rail. The high pressure fuel pump also contains an integrated pressure relief valve.
Your best bet is have it towed to the dealer , you don't want to mess with the high pressure pump .
Pluse

if the system includes the ecm to give power to a pump relay when required then the ecm will stop the pump working at times when the fuel pressure reaches the regulated pressure
I would be looking else where ,like having a pressure test done on the fuel system to find if relay, pump or regulator/ pressure sensor fault

check for a problem fuel pressure regulator
most are wired to the ECM which is connected to the relay for the pump
it works like this
with low / no fuel pressure the regulator completes a circuit to the ECM
that signal is then sent to a relay to start the pump
when full pressure is reached , the regulator signals the ECM and the relay is turned off hence the pump is not continually running when pressure is not required

I don't think the EFI relay is at fault. Other things would be dead if it was, including the starter. See here p177 to test fuel pressure, which may be too low if the fuel pump itself or the pressure regulator is faulty.

http://www.turboninjas.com/camry/eg1.pdf

Hi.

You connect a fuel pressure gauge like this to the pressure rail. Pressure in this car must be between 35 and 45 psi. If pressure is too low look for kinked fuel lines and eventually replace the pump. If the pressure drops down more than 10 psi in five minutes or if the pressure is considerably higher than that replace the fuel pressure regulator. Below the parts that may need testing:



1. Fuel tank
2. Shut-off valve
3. Non-return valve
4. Fuel pump
5. Fuel pump (Transfer)
6. Fuel filter (High-pressure)
7. Injector
8. Pressure regulator
9. PRC solenoid valve
10. Fuel pump relay
11. Fuel pump resistor and relay (KJ model)

Hi.

Check the fuel filter and fuel pressure regulator. They are part of the same assembly and are located on top of the fuel pump. To replace the regulator # Disconnect fuel supply line at the Filter/Regulator nipple and releas locking spring tab (2 in diag.) on the regulator, then turn counterclockwise and pull out. To test regulator use a gauge like this in fuel lines:Pump Pressure Tester.
Pressure in 2003 should be 58psi (48 in 2001 engines). Pressure will drop of about ten psi when you start engine.

There is also an automatic shut down relay ASR. If problem is the ASR the pressure will go down when the relay cuts off power to pump. Read voltages and see if the problem is electrical first before going for the regulator.

Keep in mind that you have several components there:
- Fuel Pump Sender Assembly,
- Fuel Pressure Regulator,
- Fuel Rail Assembly, and
- Fuel Injectors.

1.- Fuel Pump (Sender Assembly) - TESTING
Refer to the accompanying charts for fuel pump diagnosis and testing.

The fuel injection system remains under pressure, even after the engine has been turned OFF. The fuel system pressure must be relieved before disconnecting any fuel lines. Failure to do so may result in fire and/or personal injury.



Fig. 3.1L engine OBD system check to be done before fuel pump relay circuit diagnosis




Fig. 3.1L engine fuel pump relay circuit diagnosis (1 of 2)




Fig. 3.1L engine fuel pump relay circuit diagnosis (2 of 2)




Fig. View of the fuel pressure test port (Schrader valve)-3.1L engine

A - 3.1L engine fuel system pressure test (1 of 4)
B - 3.1L engine fuel system pressure test (2 of 4)
C - 3.1L engine fuel system pressure test (3 of 4)
D - 3.1L engine fuel system pressure test (4 of 4)



Fig. The fuel pump/fuel sender module assembly is mounted in the fuel tank


2.- Fuel Pressure Regulator - REMOVAL & INSTALLATION

(the fuel pressure regulator, which is located on the fuel rail assembly)

NOTE: Before removing the fuel regulator assembly, place a clean shop towel under the regulator to catch any fuel drips

1. Properly relieve the fuel system pressure.
2. If not done already, disconnect the negative battery cable.
3. On the 3.1L engine, remove the intake manifold plenum, as outlined in .
4. On the 2.4L engine, remove the fuel rail. Refer to procedure earlier in this section.
5. Detach the vacuum line from the regulator.
6. Place a shop towel under the regulator to catch any fuel that may drip out. Unfasten the fuel pressure regulator retaining screw, then remove the regulator by twisting and pulling it from the fuel rail.
7. Remove and discard the O-ring seal. Inspect the filter screen for contamination and replace if necessary.
   

To install:

1. Prior to assembling the pressure regulator to the fuel rail, lubricate the new rail-to-regulator O-ring seal with clean engine oil.
2. Place the O-ring on the pressure regulator and install the pressure regulator to the fuel rail.
3. Install the retainer or coat the regulator mounting screws with an approved thread locking compound and secure the pressure regulator in place. Tighten the mounting screw to 76 inch lbs. (8.5 Nm).
4. If removed, install the fuel rail assembly to the engine.

WARNING The fuel return pipe must be connected before tightening the regulator retaining screw to prevent the regulator from rotating. Rotation of the regulator could damage the retainer and spacer bracket and lead to a fuel leak at the regulator inlet.

1. Connect the fuel feed line and return line to the fuel rail assembly, use a backup wrench on the fittings to prevent turning.
2. Attach the vacuum line to the regulator.
3. On the 3.1L engine, install the intake manifold plenum.
4. Connect the negative battery cable. Turn the ignition to the ON position for two seconds, then turn it to the OFF position for ten seconds. Turn again to the ON position and check for fuel leaks.

continue...

Release fuel pressure by removing fuel pump relay and turning engine over to release pressure. Place a rag to catch any fuel under regulator Fuel pressure regulator has a locking clip pry clip off remove vacuum line pull regulator out with twisting motion,replace fuel pressure regulator install clip connect vacuum line install relay. Check for leaks,your done.

On that one it actually called circuit opening relay under left side of dash in fuse relay box