Fuel - Pump Volume Delivery Test
NO.: TSB-93-13-005DATE: September, 1993
MODEL: All 1993 vehicles
SUBJECT:
FUEL VOLUME DELIVERY TEST
PURPOSE
Fuel volume delivery tests have been carefully demonstrated during Electronic Controlled Injection (ECI) classes in MMSA training centers. This bulletin provides technicians with basic testing procedures and fuel volume delivery specifications. If during diagnosis of the fuel system (after a fuel pressure test has been performed - in accordance with procedures shown in the appropriate service manual) an inadequate fuel volume delivery is suspected, use the procedures shown in this bulletin and class materials.
FUEL DELIVERY VOLUME TEST
WARNING:
Gasoline is extremely flammable and explosive.
Before attempting any fuel volume delivery tests:
A. Move the vehicle to a well ventilated and well lighted area.
B. Make certain that no sources of ignition are NEAR the repair area. I.E. Pilot lights, cigarettes, cigarette lighters, electrical motors, electrical switches, metallic tools striking the floor, etc. Gasoline vapors are heavier than air, will "travel" along the ground and may find a source of ignition several yards/meters away from the source of the gasoline vapors.
C. Note the location of fire extinguishers and if necessary, temporarily move the extinguisher into the immediate testing area vicinity.
D. Wipe up any gasoline spills immediately.
E. Dispose of gasoline in accordance with Federal, State, and Local requirements.
F. Contain the fuel in an unbreakable, non-dissolvable measuring container.
1. Remove the fuel fill cap. This will relieve any pressure contained in the fuel tank. Reinstall the fuel fill cap.
2. Relieve residual fuel line pressure before disconnecting any fuel hoses.
3. Perform a fuel pressure test in accordance with the appropriate service manual.
4. Disconnect the fuel return hose from the pressure regulator and plug the hose. Connect an extension hose to the pressure regulator. The hose should be long enough to extend out of the vehicle's engine compartment and reach a suitable measuring container.
5. Place the end of the extension hose into an unbreakable, non-dissolvable measuring container.
6. Connect the Scan Tool (MUT or MUT-II) to the vehicle's diagnostic connector.
7. Turn the ignition key to the "ON" position.
8. On the Scan Tool, select the appropriate vehicle, actuator test, and activate fuel pump.
Note:
The Scan Tool will activate the fuel pump for 6 seconds.
9. Record the amount of delivered fuel.
WARNING:
Wipe up any fuel spills immediately.
10. Dispose of gasoline in accordance with all Federal, State, and Local requirements.
11. Turn the ignition off, disconnect the Scan Tool, and reconnect the fuel return line.
WARNING:
Wipe up any fuel spills immediately.
FUEL VOLUME DELIVERY SPECIFICATION
Note:
A. If the fuel volume is within specifications, the fuel pump system is providing sufficient fuel for proper engine operation.
B. If the fuel volume is below specifications, the condition can be caused by restrictions in the fuel line (in-tank strainer or fuel filter clogged, fuel hoses twisted, lines pinched), an improperly operating fuel pump, or a fuel pressure regulator.