JET VALVES | REMOVAL AND INSTALLATION NOTE: Jet valves are used on 1986-89 Excels and Sonatas with 4-cylinder engines. 9See Figures 84,85, 87 and 88).

1. Remove the rocker arm assemblies.
2. Using special socket tool MD998310 (09222-21300), remove the jet valve. Care must be taken not to twist the socket while removing the valve, it can be easily broken.
3. The valve may be disassembled using special tool MD998309 (90222-21400). Using the tool, compress the spring and remove the valve retainer lock. Remove the spring retainer and spring. Don?t separate the jet valve from the valve body or leakage and improper operation will results. Using pliers, pull off the valve stem seal and discard them.
4. Make sure that the valve slides smoothly in the valve body. If any roughness or sticking is noted or any other damage is found, replace the valve and valve body as a unit.
5. Check the valve head and seat for wear, damage and binding. The valve stem diameter should be 4.30 mm. The angle of the valve face and seat is 45. The jet valve spring free length should be 29.6000mm for both Excel and Sonata and its load at length should be 5 1/2 lbs. @21.5mm for Excel and 7.7 lbs. @21.5mm for Sonata.
6. Using special jet valve seal installed MD998308 (09222-21400) drive the new seal onto the valve body. If this tool is not used, the seal could become deforms and oil will leak into the combustion chamber.
7. Using MD998309 (09222-21500), compress the valve spring and reinstall the retainer locks.
8. Apply a coat of clean engine oil to a new O-ring and install it in the groove in the jet valve body.
9. Apply a coat of clean engine oil to the threaded portion of the valve body and seating surface and thread the assembly into place in the head using finger pressure only.
10. When the valve body is seated in the head, tighten it, with tool MD998310 (09222-21300), to 13-16 ft. lbs. Be very careful to keep the tool perfectly straight on the valve body to prevent distortion or damage to the valve assembly.

FUEL INJECTORS | REMOVAL AND INSTALLATION
1596cc, 1796cc and 1997cc ENGINES NOTE: Fuel injectors are injection nozzles with solenoid valves. They?re responsible for injecting the fuel into the intake manifold at precisely the right instant based on signals from the engine?s electronic control unit (ECU). (See Figures 56, 57, 58, 59 and 60).

1. Relieve the fuel system pressure.
2. Disconnect the negative battery cable.
3. Wrap the connection with a shop towel and disconnect the high pressure fuel line at the fuel rail.
4. Disconnect the fuel return hose.
5. Disconnect the vacuum hose from the fuel pressure regulator. Remove the fuel pressure regulator and O-ring.
6. Disconnect and remove the PCV hose.
7. Label and disconnect the electrical connectors from each injector.
8. Remove the injector rail retaining bolts. Make sure the rubber mounting bushings do not get lost.
9. Lift the rail assembly up and away from the engine.
10. Remove the injectors from the rail by pulling gently. Discard the lower insulator. Check the resistance through the injector. The specification is 13-16 ohms at 70øF (20øC). If resistance is out of desired reading, replace the injector.
TO INSTALL:
11. Install a new grommet and O-ring to the injector. Coat the O-ring with light oil.
12. Install the injector to the fuel rail turning to the left and right during installation.
13. Install the fuel rail and injectors to the manifold. Make sure the rubber bushings are in place before tightening the mounting bolts.
14. Tighten the retaining bolts to 72 inch lbs. (11Nm).
15. Connect the electrical harness connectors to the injectors. Install and connect the PCV hose.
16. Replace the O-ring, lightly lubricate it and connect the fuel pressure regulator.
17. Connect the fuel return hose.
18. Replace the O-ring, lightly lubricate it and connect the high pressure fuel line.
19. Connect the negative battery cable and check the entire system for proper operation and leaks.