Fuel Injector: Service and Repair

REMOVAL
Do not remove or disassemble the ISC servo assembly, throttle valve or fuel return nipple.
1. Disconnect battery ground cable, then drain engine coolant.
2. Disconnect air intake hose from throttle body.
3. Remove water hose, connected between intake manifold, throttle body and water inlet pipe, at throttle body nipple.
4. Disconnect throttle cable from surge tank, rocker cover and throttle lever of throttle body, then remove breather hose.
5. Disconnect vacuum hoses connected between pressure regulator, vacuum regulator valve, throttle body, surge tank, thermo valve, distributor and solenoid valve.
6. Disconnect injector, ISC servo and throttle position sensor electrical connectors.
7. Disconnect fuel supply and return hoses from delivery pipe. Before removing fuel high pressure hose, loosen bolts slightly to allow residual pressure to escape.
8. Remove surge tank attaching nuts and bolts, then the surge tank.
9. Remove 4 throttle body assembly attaching bolts, then the throttle body assembly.
10. Remove delivery pipe attaching bolts, then the delivery pipe together with injectors.
11. Remove fuel injectors from delivery pipe, then the insulators from intake manifold.
12. Remove ignition coil.
13. Disconnect hose which connects EGR valve and vacuum regulator valve, then remove vacuum regulator valve bracket and EGR valve.
14. Remove vacuum pipe assembly attaching bolts, then the vacuum pipe assembly.
15. Remove fuel pulsation damper from delivery pipe.
16. Remove pressure regulator.

Fig. 15 Pressure regulator installation.:

Fig. 16 Vacuum hose installation.:

INSTALLATION
Reverse removal procedure to install, noting the following:
1. Install new grommet and O-ring on injector.
2. Apply gasoline or spindle oil on injector O-rings to facilitate installation. Use caution not to scratch or damage O-ring during installation.
3. Torque delivery pipe to intake manifold attaching bolts to 8 ft. lbs.
4. Ensure fuel injectors are properly seated.
5. Align nipple of pressure regulator as shown in Fig. 15, then torque pressure regulator attaching nut to 18 - 25 ft. lbs.
6. Torque fuel pulsation damper to 26 - 32 ft. lbs.
7. Install vacuum hoses as shown in Fig. 16.