How do I identify bmw intake and outlet fuel lines

Hi it seems like an air leak in the intake manifold. Check all the vacuum lines around the throttle body and the brake servo line. A small leak will cause the throttle to fluctuate, and also affect the fuel trim. You may also need to clean or replace the throttle body. Good luck

Can you identify or remember which pipe on the sending unit, the pump module, is the main outlet from the pump?
The three lines are the main feed or pressure line to the engine, the return line from the engine to the tank-this line is often smaller than the main line. And the third line is not a fuel line, but the vent line for fumes from the enclosed tank to the charcoal canister. This line may be identifiable by pipe diameter being smaller, or sometimes using rubber hoses with it, or maybe just a little offstanding from the other two lines. The main line (pressure line) will be the line that has the fuel filter in it. You can identify the main line this way, then just figure out where it connects onto the tank, and sort out the other two lines-the return line and the (?smaller?) vent line.

Check the wiring and the lines first. INspect the fuel filter. It may have some loose vacuum lines or worn out ones. Check the idle air control valve and the MAF sensor in the intake it may need some cleaning. If you can, have a scanner connected to the car. Some shops would let you borrow their scanner. The error would help identify the issue more accurately.

The first thing I would look at is changing fuel filter. Then check engine compartment ALL small vac lines and air intake hose. You might also consider running a good fuel system cleaner through it.

FUEL PRESSURE REGULATOR IS ON FUEL RAIL WITH THE FUEL INJECTORS.THE FUEL PRESSURE REGULATOR ALSO HAS A VACUUM LINE GOING TO IT.THE FUEL INJECTORS AND FUEL PRESSURE REGULATOR IS UNDER THE INTAKE COVER.

Bonneville, LeSabre, Park Avenue 2000-2005 Intake Manifold - Removal & Installation

3.8L Engine
VIN 1 Engine

1. Before servicing the vehicle, refer to the Precautions section.
2. Relieve the fuel system pressure.
3. Drain the cooling system.
4. Remove or disconnect the following:
   Negative battery cable Supercharger Thermostat housing Exhaust Gas Recirculation (EGR) tube at the intake manifold Engine Control Temperature (ECT) sensor Intake manifold

To install:

1. Install or connect the following:
   Intake manifold with new gaskets. Torque the bolts, working from the center out, to 11 ft. lbs. (15 Nm). ECT sensor connector EGR tube to the intake manifold Thermostat housing Supercharger Negative battery cable
2. Refill and bleed the cooling system.
3. Run the engine and check for leaks and proper engine operation.

VIN K Engine

1. Before servicing the vehicle, refer to the Precautions section.
2. Disconnect the negative battery cable.
3. Drain the cooling system.
4. Relieve the fuel system pressure.
5. Remove or disconnect the following:
   Fuel injector sight shield Air inlet duct Spark plug wires from the right side Manifold Absolute Pressure (MAP) sensor Vacuum lines from the intake manifold Fuel lines Fuel injector electrical connectors Fuel regulator vacuum line Fuel rail from the intake manifold Exhaust Gas Recirculation (EGR) heat shield Throttle cable bracket from the cylinder head mounting bracket and the throttle body cables Throttle body support bracket Upper intake plenum and gasket Thermostat housing Electrical connector from the Engine Coolant Temperature (ECT) sensor Drive belt tensioner assembly EGR valve outlet pipe Lower intake manifold
   
   
   Fig. Exploded view of the intake manifold and related components-3.8L (VIN K) engine
   

To install:



Fig. Upper intake manifold torque sequence-3.8L (VIN K) engine



Fig. Lower intake manifold torque sequence-3.8L (VIN K) engine

1. Install or connect the following:
   Intake manifold using new manifold gaskets. Torque the bolts in sequence to 11 ft. lbs. (15 Nm); then, re-torque to 11 ft. lbs. (15 Nm). EGR valve outlet pipe Drive belt tensioner assembly. Torque the tensioner bolts to 37 ft. lbs. (50 Nm). Electrical connector to the ECT sensor Thermostat housing Upper intake plenum. Torque the intake plenum bolts to 88 inch. lbs. (10 Nm). Throttle body support bracket Throttle cable bracket to the cylinder head mounting bracket and the cables to the throttle body lever EGR heat shield Fuel rail. Torque the fuel rail bolts to 88 inch. lbs. (10 Nm). Fuel lines Fuel regulator vacuum line Fuel injector electrical connectors Vacuum lines to the intake manifold MAP sensor Spark plug wires Fuel injector sight shield and air inlet duct Negative battery cable
2. Refill and bleed the cooling system.
3. Run the engine and check for leaks and proper engine operation.

Hope this help (remember rated this).

on some it is down behind engine , just lean in looking down by each side back of motor also you can follow the fuel line from intake back to locate it.

The vortec motor has been known for the so caller spider assembly which is the fuel injection set up inside the intake manifold going bad.The regulator starts leaking wich puts extra fuel into the motor.If that is it you should change the whole assembly.