GM Full-Size Trucks 1988-1998 Repair Information Electric Fuel Pump
* REMOVAL & INSTALLATION * TESTING
CAUTION The 220 TBI unit has a bleed in the pressure regulator to relieve pressure any time the engine is turned off, however a small amount of fuel may be released when the fuel line is disconnected. As a precaution, cover the fuel line with a cloth and dispose of properly.
Electric fuel pump-TBI engines
1. With the engine turned OFF , relieve the fuel pressure at the pressure regulator. Refer to the fuel relief procedure in this section.
2. Disconnect the negative battery cable.
3. Raise and support the rear of the vehicle on jackstands.
4. Drain the fuel tank, then remove it.
5. Using a hammer and a drift punch, drive the fuel lever sending device and pump assembly locking ring (located on top of the fuel tank) counterclockwise. Lift the assembly from the tank and remove the pump from the fuel lever sending device.
6. Pull the pump up into the attaching hose while pulling it outward away from the bottom support. Be careful not to damage the rubber insulator and strainer during removal. After the pump assembly is clear of the bottom support, pull it out of the rubber connector.
7. Connect the fuel pump to the hose.
Be careful that you don't fold or twist the strainer when installing the sending unit, or you'll restrict fuel flow.
8. Install a new O-ring on the pump assembly and then position them into the fuel tank.
9. Turn the locking ring clockwise until its tight.
10. Install the fuel tank and connect the battery cable.
Special tools J-29658-82 and J-29658, or their equivalents, will be necessary for this procedure.
1. Disconnect the negative battery cable.
2. Secure two sections of 3 / 8 in. x 10 in. (9.5mm x 254mm) steel tubing, with a double-flare on one end of each section.
3. Install a flare nut on each section of tubing, then connect each of the sections into the flare nut-to-flare nut adapter, while care included in the gauge adapter tool No. J-29658-82 or equivalent.
4. Attach the pipe and the adapter assembly to the gauge tool No. J-29658 or equivalent.
5. Raise and support the vehicle on jackstands.
6. Remove the air cleaner and plug the THERMAC vacuum port on the TBI.
7. Disconnect the fuel feed hose between the fuel tank and the filter, then secure the other ends of the 3 / 8 in. (9.5mm) tubing into the fuel hoses with hose clamps.
8. Reconnect the battery cable.
9. Start the engine, check for leaks and observe the fuel pressure, it should be 9-13 psi (62-89 kPa).
10. Depressurize the fuel system, remove the testing tool, remove the plug from the THERMAC vacuum port, reconnect the fuel line, start the engine and check for fuel leaks.