Technical Car Experts Answers everything you need: how to fit the o-ring from fuel line to cylinder on Chevy Astro Van?

Fuel injectors operate in conjunction with a high pressure fuel system. The fuel injector head is connected to the fuel line and engine through a O-ring seal. The O-ring allows the injector to be seated, in both the fuel line and engine, without requiring bolts, screws or threaded connectors. Injector leaks stemming from poor O-ring connections may be caused by O-ring shrinkage, exposure to high heat, chemical decomposition, or tears in the O-ring material.

Press the injector straight down, nozzle first, into the fuel injector hole. You may feel a slight popping sensation as the O-ring is seated properly. Correctly installed fuel injectors will resist removal when you pull upward on the injector.

Press the fuel line onto the injector top. As with the seating of the fuel injector in the engine, a slight popping sensation may be felt and the fuel rail will resist removal.

REMOVAL & INSTALLATION

See Figure 1

Fig. Fig. 1: Servicing quick connect fittings

This procedure requires Tool Set J37088-A or an equivalent aftermarket fuel line quick-connect separator.

Grasp both sides of the fitting. Twist the female connector ¹ / ₄ turn in each direction to loosen any dirt within the fittings. Using compressed air, blow out the dirt from the quick-connect fittings at the end of the fittings.

CAUTION

Safety glasses MUST be worn when using compressed air to avoid eye injury due to flying dirt particles!

For plastic (hand releasable) fittings, squeeze the plastic retainer release tabs, then pull the connection apart.

For metal fittings, choose the correct tool from kit J37088-A or its equivalent for the size of the fitting to be disconnected. Insert the proper tool into the female connector, then push inward to release the locking tabs. Pull the connection apart.

If it is necessary to remove rust or burrs from the male tube end of a quick-connect fitting, use emery cloth in a radial motion with the tube end to prevent damage to the O-ring sealing surfaces. Using a clean shop towel, wipe off the male tube ends. Inspect all connectors for dirt and burrs. Clean and/or replace if required.

To install:

Apply a few drops of clean engine oil to the male tube end of the fitting.

Push the connectors together to cause the retaining tabs/fingers to snap into place.

Once installed, pull on both ends of each connection to make sure they are secure and check for leaks.

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Fuel Injectors

REMOVAL & INSTALLATION

See Figure 1

Fig. Fig. 1: The fuel pump and fuel gauge sender are incorporated in one unit mounted in the fuel tank

The electric fuel pump is attached to the fuel sending unit, located in the fuel tank.

REMOVAL & INSTALLATION

Because removal and installation of the fuel pump requires the removal of the fuel tank, refer to the procedures in the fuel tank portion of this section.

TESTING

Flow Test

Relieve the fuel system pressure.

Remove the fuel pump feed line from the fuel inlet on the throttle body.

Place the fuel line in a clean container.

Turn the ignition switch ON ; approximately ¹ / ₂ pint of the fuel should be delivered in 15 seconds.

If the fuel flow is below minimum, inspect the fuel system for restrictions; if no restrictions are found, replace the fuel pump.

Pressure Test

See Figure 2

Fig. Fig. 2: Fuel system pressure testing

The following procedure requires the use of a GM Fuel Pressure Gauge tool No. J-29658-A or equivalent.

Properly relieve the fuel system pressure.

If necessary for access, remove the air cleaner assembly and plug the vacuum port(s).

Disconnect the flexible fuel supply line, located in the engine compartment between the fuel filter and throttle body.

Install a fuel pressure gauge, such as J-29658 or equivalent, in-line between the fuel filter and throttle body unit (between the steel line and flexible hose). If necessary use an adapter or Tee fitting in order to connect the gauge and complete the fuel circuit.

A Tee fitting may be fabricated for this purpose. Depending on the fuel pressure gauge, short lengths of steel tubing, appropriately sized flare nuts and a flare nut adapter may be used.

If the engine will run, start the engine and allow it to run at normal idle speed. The fuel pressure should be 9-13 psi (62-90 kPa).

If the engine does not run, turn the ignition ON , but do not attempt to start the engine. Listen for the fuel pump to run. Within 2 seconds of turning the ignition ON , pressure should be 9-13 psi (62-90 kPa). If necessary, cycle the ignition OFF , then ON again, in order to build up system pressure.

If the fuel pump did not run or system pressure did not reach specification, locate the fuel pump test connector. The test connector is usually found on the driver's side of the engine compartment (on or near the fender), with a single wire (usually red) leading from the relay to the connector. Using a jumper wire, apply battery voltage to the test connector in order to energize and run the fuel pump. The pump should run and produce fuel pressure of 9-13 psi (62-90 kPa). If the pump does not run, check the relay and fuel pump wiring.

If the pump pressure was lower than specification, first check for a restricted fuel line or filter and replace, as necessary. If no restrictions can be found, restrict the fuel supply line between the pressure gauge and the TBI unit (a flexible hose may be temporarily clamped to produce the restriction), then apply voltage to the test connector again. If pressure is now above 13 psi (90 kPa), replace the faulty pressure regulator. If pressure remains below 9 psi (62 kPa), then the problem is located in the fuel tank (the fuel pump, coupling hose or inlet filter).

If during Step 7, the pressure was higher than specification, disengage the injector connector, then disconnect the fuel return line flexible hose which connects the line from the throttle body to the tank line. Attach a⁵ / ₁₆ ID flex hose to the fuel line from the throttle body and place the other end into an approved gasoline container. Cycle the ignition in order to energize the fuel pump and watch system pressure. If pressure is still higher, check for restrictions in the throttle body return line. Repair or replace the line if restrictions are found or replace the faulty pressure regulator if no other causes of high pressure are identified. If fuel pressure is normal only with the flexible hose-to-fuel tank line out of the circuit, check that line for restrictions and repair or replace, as necessary.

Once the test is completed, depressurize the fuel system and remove the gauge.

Secure the fuel lines and check for leaks.

If removed, install the air cleaner assembly.

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Fuel Meter Cover

REMOVAL & INSTALLATION

REMOVAL & INSTALLATION

See Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12

Fig. Fig. 1: Removing the fuel meter cover from the throttle body-Model 300 (Model 220 is similar)

Fig. Fig. 2: The throttle body can be accessed once the engine cover and air cleaner have been removed

Fig. Fig. 3: Remove the adapter ring and disconnect from the breather hose

Fig. Fig. 4: Unplug the injector electrical connectors

Fig. Fig. 5: Use clean rags to block the throttle openings and prevent debris from dropping in the engine

Fig. Fig. 6: Remove the mounting screws from the meter body

Fig. Fig. 7: Lift the meter body up and off the injectors. The injectors can be removed at this point

Fig. Fig. 8: Check the condition of the gaskets. This one is torn and would leak fuel if reused

Fig. Fig. 9: The fuel pressure regulator can be removed from the meter cover

Fig. Fig. 10: The fuel pressure regulator diaphragm must be intact for proper operation

Fig. Fig. 11: Check the condition of the diaphragm and seating area before reassembly

Fig. Fig. 12: Exploded view of the fuel metering cover

The fuel meter cover does not have to be removed to replace the single fuel injector for the Model 700 throttle body (1987-90 2.5L engine). For the Model 220 and 300, the fuel meter cover does have to be removed to replace the injector.

Remove the air cleaner. Disconnect the negative battery cable from the battery.

At the injector electrical connector, squeeze the 2 tabs together and pull it straight up.

Remove the fuel meter-to-fuel meter body screws and lockwashers.

When removing the fuel meter cover screws, note the location of the two short screws.

Remove the fuel meter cover and discard the gasket.

To install:

Use a new gasket and install the injector if removed.

Install the fuel meter cover and torque the screws to 30 inch lbs. (4.0 Nm).

Reconnect the injector electrical connector and negative battery cable.

Start the engine, check for leaks and proper operation.

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Fuel Pump Relay

REMOVAL & INSTALLATION

See Figure 1

Fig. Fig. 1: Fuel pump relay location

The fuel pump relay is mounted on the right-side of the engine compartment. Check for loose electrical connections; no other service is possible, except replacement.