Fuel Pump - Electric Dodge Caravan I

COMPONENT TESTING

Note. Specific component testing information not available. Refer to any tests performed during REMOVAL & INSTALLATION or OVERHAUL procedures

DESCRIPTION & OPERATION

Single point (2.5L) and multi-point (3.0L) fuel injection models use 2 different types of electric fuel pumps. (Scheme 28) Pumps are NOT interchangeable due to different operating pressures Failure to use correct pump may cause serious damage to fuel system components.

All Throttle Body Injection (TBI) models operate under a constant fuel pressure of 14.7 psi (1.03 kg/cm 2 ). Pump is an immersible type with permanent magnet electric motor. Fuel is drawn in through a filter sock and pushed through electric motor to pump outlet.

A check valve, located near pump outlet, restricts fuel movement in either direction when pump is not in operation. Voltage to operate pump is supplied through Auto Shutdown Relay. Before servicing fuel tank, throttle body, pump, fuel lines or filter, system fuel zpressure must be released. See FUEL PUMP PRESSURE RELEASE .

A positive displacement, roller vane pump is used on all 3.0L Electronic Fuel Injection (EFI) models. Pump is located in fuel tank. A permanent magnet electric motor is used. Operating voltage is supplied through Auto Shutdown Relay.

Fuel is drawn in through a filter sock and pushed through motor to outlet. Pump contains 2 check valves. One valve relieves internal pump pressure and regulates maximum pump output. Second valve, located near pump outlet, restricts fuel movement in either direction when pump is not in operation.

System operates under a constant fuel pressure of 36 psi (2.53 kg/cm 2 ). Before servicing fuel tank, pump, lines, filter or components of the fuel rail, system fuel pressure must be released. See FUEL PUMP PRESSURE RELEASE .

2.5L TBI & 3.0L MPFI Fuel Pumps Pumps are not interchangeable. Courtesy of Chrysler Motors. Scheme 28

All Models

1. Loosen gasoline cap to release tank pressure.
2. Remove wiring harness connector from injector.
3. Ground one injector terminal with a jumper wire.
4. Connect jumper wire to second terminal and touch battery positive post for no longer than 10 seconds.
5. Remove jumper wires.
6. Continue fuel system service.

2.5L TBI Models

1. Release pressure each time a fuel hose is to be disconnected. Disconnect 5/16" fuel supply hose from engine fuel line assembly. Connect Testers (C-3292 and C-4749) between fuel supply hose and engine fuel line assembly. Install ATM Tester (C-4805). Place ignition switch in "RUN" position.
2. Depress ATM button to activate fuel pump and pressurize system. If gauge reading is 13.5-15.5 psi (.949-1.08 kg/cm 2 ), pressure is correct and no further testing is required. Reinstall fuel hose using new original equipment clamp. Tighten clamp to 10 In. lbs. (.85 N.m.).
3. If fuel pressure is below specifications, install tester between fuel supply tube and fuel filter inlet hose. Repeat test. If pressure now meets specifications, replace fuel filter. If no change is observed, gently squeeze return hose. If pressure increases, replace pressure regulator. If no change is observed, pump filter sock is plugged or fuel pump is defective.
4. If pressure is above specifications, remove fuel return hose from throttle body. Connect a substitute hose to body and place other end of hose in a clean container. Repeat test. If pressure is now correct, check for restricted fuel return line. If no change is observed, replace fuel regulator.

3.0L MPFI Models

1. Release pressure each time a fuel hose is to be disconnected. Disconnect 5/16" fuel supply hose from engine fuel line assembly. Connect Testers (C-3292 and C-4749) between fuel supply hose and engine fuel line assembly. Install ATM Tester (C-4805). Place ignition switch in "RUN" position.
2. Depress ATM button to activate fuel pump and pressurize system. If gauge reading is 34-38 psi (2.39-2.67 kg/cm 2 ), pressure is correct and no further testing is required.
3. If fuel pressure is below specifications, install tester between fuel supply tube and fuel filter inlet hose. Repeat test. If pressure now meets specifications, replace fuel filter.

Removal

1. Remove fuel tank. Use a hammer and brass punch to remove lock ring. Rotate pump lock ring counterclockwise to release fuel pump. Lift fuel pump assembly out of tank until return line hose connection is visible at intake end of pump assembly. (Scheme 29)
2. Disconnect fuel fitting by pressing on fuel fitting ears with thumb and forefinger. Remove pump assembly from tank with "O" ring seal. Discard seal and pump inlet filter.

Scheme 29

Scheme 30

Installation

Clean seal contact area of fuel tank. Install a new "O" ring seal on pump. Install a new filter on end of suction tube. Connect reservoir hose to pump assembly at suction end of pump. Position pump in tank with locking ring. To complete installation, reverse removal procedure. Start engine and check for leaks.

See also:
• FUEL PUMP PRESSURE RELEASE