Fuel pump relay diagrams

Check the fuel pump relay switch. According to a post on the Ford Truck Enthusiasts Forums, the fuel pump relay switch is located under the PDB (Power Distribution Box) . You may need to refer to the wiring diagram to locate it. If you don't have one, you can request it from the same post.

Check the fuel pump cutoff switch. This switch is located behind the firewall and is designed to shut off the fuel supply in case of an accident .

Check the fuel rail pressure regulator. If the fuel pump and the fuel cutoff switch are working fine, then the problem might be with the fuel rail pressure regulator. This is a small can mounted inline with the fuel rail with a vacuum hose attached to a hose barb on top of the unit .

Usually if cranks good but won't start, you have a helper crank it while you visually check for spark at the spark plugs. If spark everywhere, use a gage and check proper fuel pressure and check fuel injector pulse. I don't know what testing you have done?
As far as the fuel regulator, it depends? If there is a return line, the pressure regulator should be on the fuel rail. If no return line, with mechanical returnless, the regulator may be in a loop close to gas tank. With electronic returnless, everything is in the gas tank. Sorry, I haven't found any pictures?

check fuses and relays fuel pumps pressurize for a couple of seconds then hum stops -check for pressure at fuel rail - power at relay and power to and at pump and inspect the connections at each and pump is in fuel tank but with rear seat access remove rear seat and access plate -and fuel pump will be right in front of you
02 galant fuel pump Yahoo Video Search Results

1.6L or 1.8L vastly different engines... and EFI.
fuel to the rail , only means the pump is active , never good.
28PSI is minimum on all cars. 1psi will never start a car. ever
and the rail will shoot fuel, all day. it fruitless , unless the rail is dead.
see?
First the laws of EFI. (works all gas EFI)

1. all fuses good.
2. 12vdc to EFI system , below 10v is bad. (see lamps dim? bingo)
3. The PCM (EFI brain) will never inject if it sees CMP/CKP or spark primary dead. ever. so, spark is first.

that is double reasons, fuel cant burn if no spark and if ECU
thinks spark is bad it cuts fuel, (fire safety and fuel hydralocking reasons)

so you connect any scan tool to the DLC, OBD2 port , by knees.
and crank for 5 seconds, release key, no turn off
see DTCs (errors) for CMP, or CKP sensors (cam/crank?)
bingo
no, then you crank and look at the RPM PID , live data stream the scan tool, see RPM go to 250rpm cranking, good.
ok , PCM thinks all is good....

i then check the #1 injector with a NOID lamp
i crank it flashes, good.
if not , i do all injectors , if one fails the pcm is dead on this line.
if yes, all dont flash the PCM is seeing some gross errors. ask. why./?
if all flash, then the fuel rail is dead. and your rail test was useless.

until you discloses engine option (size) I cant give spec numbers.
i then connect my fuel pressure gauge $20 tool to the fuel rail test
port, and i get 10psi, FAIL
i check voltage to the fuel pump cranking, i get 8v, bingo bad wiring
or bad fuel pump relay.
say 10psi and 12v at pump cranking,
the pump is bad, or the filter clogged , or the fuel pressure regulator
is stuck wide open killing all legit pressure.

that is how i do it.
keep in mind the PCM cant see fuel pressure on most cars.
some newer cars have this sensors. (nice)
low fuel pressure,. renders the whole EFI , useless. just junk.

Did you check the fuel pump relay ? The relay gets power from a fuse and also from the PCM relay. The computer grounds the relay to turn it on for 3 seconds when you turn the key on, then only after the computer "sees" RPM or oil pressure.

Fuel Pressure Regulator is located on the fuel rail.

1. Disconnect the negative battery cable.

2. Properly relieve the fuel system pressure.

3. Remove the air cleaner outlet tube(s).

4. Remove any necessary components to access the pressure regulator.

5. Disconnect the vacuum hose from the pressure regulator.

6. Remove the pressure regulator attaching screws.

7. Remove the pressure regulator from the fuel rail.

To Install

8. Discard the O-rings on the pressure regulator and replace them with new ones.

9. Lubricate the O-rings with clean engine oil.

10. Install the regulator into the fuel rail and tighten the retaining screws.

11. Connect the vacuum hose to the regulator.

12. Install any components removed to access the regulator.

13. Install the air cleaner outlet tube(s).

14. Connect the negative battery cable.

Possible bad fuel pressure regulator.(you can check this by disconnecting the vacuum supply from the regulator,if fuel is in the vacuum supply your regulator is ruptured.the regulator is located on the drivers side fuel rail in the center of the rail.)The other possiblility is the fuel pump is getting weak and cannot build pressure

Try checking your fuse and relay for the pump or the fuel pressure regulator. How are you checking for fuel? Pressure gage at fuel rail?

If you are not getting fuel pressure to the rails then you have an electrical problem such as a relay or fuse which are located in under hood fuse box, or the pressure regulator on the beginning of the fuel rail where the lines come in is bad.

fuel pressure regulator (on the fuel rail) hope this helps and good luck