No fuel to engine - LS 400 Lexus Cars & Trucks

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.

Does it have spark ? Instead of trying to test fuel pressure , spray carb cleaner into the engine through the throttle plate or vacuum hose an see if it starts an runs ,at least till carb, cleaner is used up. What engine does it have ?

Engine Controls and Fuel - 2.8L
Engine Controls and Fuel - 3.6L
Engine Controls and Fuel - 6.0L

Fuel Rail
The fuel rail consists of 3 parts:
• The pipe that carries fuel to each injector
• The fuel pressure test port
• Six individual fuel injectors
The fuel rail is mounted on the intake manifold and distributes the fuel to each cylinder through the individual injectors.

You have to take the plastic cover off the top of the engine to see it .

What engine ?
Engine Controls and Fuel - 1.2L
Engine Controls and Fuel - 1.4L (L95)
Engine Controls and Fuel - 1.4L (LDT)
Engine Controls and Fuel - 1.5L
Engine Controls and Fuel - 1.6L (LXT)
Engine Controls and Fuel - 1.6L (LXV)

2007 Chevrolet Silverado - 2WD or 4X4
2007 Chevrolet Silverado Classic - 4WD or 2WD . What size engine ?
Engine Controls and Fuel - 4.3L
Engine Controls and Fuel - 4.8L, 5.3L, and 6.0L
Engine Controls and Fuel - 6.6L (LBZ and LLY)
Engine Controls and Fuel - 8.1L

6.6 L
DTC P0191: Fuel Rail Pressure (FRP) Sensor Performance
The fuel rail pressure (FRP) sensor has a 5-volt reference circuit, a signal circuit, and a low reference circuit. The engine control module (ECM) monitors the voltage on the FRP sensor circuits. When the fuel pressure is high, the signal voltage is high. When the fuel pressure is low, the signal voltage is low. The fuel pressure regulator has a solenoid supply voltage circuit and a solenoid control circuit. The ECM controls the fuel pressure regulator , which regulates high pressure fuel that goes to the fuel injector rails and the injectors.

Check the fuel pressure. The pressure regulator may have gone bad and is delivering too much pressure to the fuel rail, thereby flooding the engine.

Check this procedure about V8 3.9L Fuel Injectors - Removal & Installation

1. Before servicing the vehicle, please familiarize yourself with safety procedures.
2. Relieve fuel system pressure.
3. Remove or disconnect the following:
   Negative battery cable Engine appearance covers Fuel lines Fuel pressure regulator Fuel cross over elbow Fuel injector connectors Fuel injector clamping plates Fuel injectors

To install:

1. Install or connect the following:
   Fuel injectors. Use new O-ring seals. Fuel injector clamping plates Fuel injector connectors Fuel cross over elbow Fuel pressure regulator Fuel lines Engine appearance covers Negative battery cable
2. Start the engine and check for leaks.
   

1. Before servicing the vehicle, please familiarize yourself with safety procedures.
2. Disconnect the negative battery cable.
   CAUTION The engine appearance cover is equipped with a noise suppressor. If the noise suppressor becomes separated from the engine appearance cover it must be positioned on the intake manifold prior to installing the engine appearance cover.
3. Remove the engine appearance cover and the noise suppressor, if detached.
4. Remove the air cleaner outlet pipe.
5. Release the fuel system pressure.
6. Remove the four engine appearance cover mounting bracket nuts and the brackets.
7. Disconnect the fuel pressure sensor electrical connector from the sensor.
8. Disconnect the fuel pressure sensor vacuum connector from the sensor.
9. Disconnect the eight fuel injector electrical connectors from the injectors.
10. Disconnect the fuel temperature sensor electrical connector from the sensor.
11. Disconnect the fuel supply tube retaining clip from the fuel injection supply manifold.
12. Disconnect the fuel supply tube spring lock coupling.
13. Remove the four bolts and the fuel injection supply manifold and fuel injectors as an assembly.
14. Remove the fuel injectors from the fuel injection supply manifold.
    CAUTION Use O-ring seals that are made of special fuel-resistant material. Use of ordinary O-ring seals can cause the fuel system to leak. Do not reuse the O-ring seals.
15. Remove and discard the 16 O-ring seals from the fuel injectors.
    
    
    

    Fig. Exploded view of the fuel injector mounting-3.9L engine shown
    

To install:

1. Lubricate the new fuel injector O-ring seals with clean engine oil before installing.
   CAUTION Use O-ring seals that are made of special fuel-resistant material. Use of ordinary O-rings can cause the fuel system to leak. Do not reuse the O-ring seals.
2. Install sixteen new O-ring seals onto the fuel injectors. Lubricate the O-ring seals with clean engine oil prior to installation.
3. Install the fuel injectors and clips onto the fuel rail.
4. Install the fuel rail and injectors as an assembly. Tighten the fuel rail bolts to 89 inch lbs. (10 Nm).
5. Install the remaining components in the reverse order of removal.

Keep us updated.

engines need 3 things to start (petrol engine)
fuel, air and a spark,
as you have been working on your fuel system it is best to suspect this system first,
on engine turn over see if you can smell fuel at the exhaust.
if you smell fuel the fuel regulation mybe too high and the engine is flooding.
if you do not smell fuel, remove fuel line from engine and ensure fuel is getting to the engine,
(be careful not to let fuel spill this generates a fire risk)..
once fuel is getting to the engine, check your ignition system to ensure you have a good spark to ignite the fuel.
finally check your air filter is not blocked and that you have air getting to the engine.

I hope this was helpful.

check your crankshaft position sensor