Engine Controls - Remove/install/overhaul Hyundai Sonata II

INTRODUCTION

Removal, overhaul and installation procedures (when given by manufacturer) are covered in this article. If component removal and installation is primarily an unbolt and bolt-on procedure, only a torque specification may be furnished.

Removal

Disconnect negative battery cable. Remove distributor cap and spark plug wires. Turn crankshaft until No. 1 cylinder is at Top Dead Center (TDC) on compression stroke. Note direction of rotor for installation. Disconnect distributor lead wire connector. Remove distributor hold-down nut and washer. Remove distributor assembly.

Disassembly

1. Lightly clamp distributor in soft-jawed vise. Remove rotor screw (on Sonata V6) and rotor, gasket and plastic cover. (Scheme 1) Remove rotor shaft screw. Remove rotor shaft (using puller if necessary).
2. Remove optical disc and spacer(s). Disconnect lead wire connector. Remove base plate mounting screws. Lift out base plate and optical unit. Remove distributor shaft bearing screws.
3. On 4-cylinder models, turn distributor shaft so flat on rotor end of distributor shaft aligns with distributor mounting flange. On all models, mark distributor shaft and gear position for reassembly. Support gear on soft wooden block and drive out roll pin. Remove gear and distributor shaft from distributor housing.

Reassembly & Installation

1. Coat distributor shaft with a small amount of engine oil. Assemble distributor shaft and housing. On 4-cylinder models, turn distributor shaft so flat on rotor end of shaft aligns with distributor mounting flange.
2. On all models, assemble drive gear to distributor shaft. Align disassembly marks on distributor shaft and gear. Install NEW roll pin. To complete reassembly, reverse disassembly procedure. Ensure optical disc slots are not clogged. To install, reverse removal procedure.

Scheme 1

CRANK ANGLE SENSOR

Note. The optical unit, containing crank angle sensor and No. 1 cylinder TDC sensor, is mounted on distributor base plate. Optical unit is removed and replaced with base plate as an assembly.

Removal & Installation

See DISTRIBUTOR in this article. (Scheme 1)

FUEL SYSTEM PRESSURE RELEASE

Fuel Pressure Release

Disconnect fuel pump harness connector at fuel tank rear side. Start engine. After engine stalls, turn ignition switch to OFF position. Disconnect negative battery cable.

1. Release fuel pressure. See FUEL PRESSURE RELEASE in this article. Remove fuel tank cap. Drain the fuel below level of fuel pump. Cover high pressure hose connection with shop towels to prevent fuel leakage. Disconnect high pressure hose at fuel tank.
2. Remove fuel pump-to-fuel tank screws. Remove fuel pump support bolt on lower side of fuel tank. Remove fuel pump assembly from fuel tank.

Installation

Install fuel pump support bolt first. Use care not to pinch "O" ring. To complete installation, reverse removal procedure.

1. Release fuel pressure. See FUEL PRESSURE RELEASE in this article. Reconnect fuel pump harness connector. On Sonata 3.0L, disconnect EGR pipe and remove intake manifold (plenum). On all models, disconnect high pressure fuel hose, while covering fitting with shop towel.
2. Unplug fuel injector harness. Remove fuel rail attaching bolts with fuel injectors and pressure regulator attached. Rotate injector while pulling outward to remove. (Scheme 2)and (Scheme 3).

1. Lightly coat new injector "O" rings (fuel rail side) with fuel. Install new insulator in intake manifold. Rotate injector while pushing into fuel rail. If injector does not turn smoothly, remove injector and check "O" ring for binding.
2. Lightly coat new injector "O" rings with fuel (intake manifold side). Position fuel rail assembly over insulators. Install injectors in intake manifold. Ensure injectors rotate smoothly. If not, check "O" ring for binding.
3. Bolt fuel rail assembly to intake manifold. Connect high pressure fuel hose to fuel rail. With ignition on and engine off, check for fuel leaks before starting engine. To complete installation, reverse removal procedure. See TORQUE SPECIFICATIONS at end of article.

Scheme 2

Scheme 3

EXHAUST GAS OXYGEN (O2) SENSOR

O2 sensor is mounted in the exhaust manifold except on Sonata 3.0L, where it is mounted downstream in exhaust pipe. O2 sensor has a permanent pigtail which must be protected from damage when the sensor is removed. Ensure sensor is free of contaminants. DO NOT use any cleaning solvents.

1. Ensure exhaust system is cool before removing O2 sensor or thread damage may occur. Disconnect negative battery cable and oxygen sensor connector. (Scheme 4) Remove oxygen sensor.
2. To install, reverse removal procedure. Apply anti-seize compound to oxygen sensor threads. Tighten to specification. See TORQUE SPECIFICATIONS at end of article.

Scheme 4

1. Disconnect negative battery cable. Drain engine coolant so level is below throttle body. Disconnect accelerator cable from throttle valve lever and cable bracket.
2. Disconnect throttle position sensor connector. Label and disconnect all vacuum hoses from throttle body. Disconnect engine coolant hoses from throttle body. Remove throttle body from intake manifold.

CLEANING & INSPECTION

1. Clean all components with solvent EXCEPT throttle position sensor and ISC servo assembly.
2. Check for restrictions in vacuum ports and passages. Blow out with compressed air. DO NOT remove throttle valve.

Using new gasket, install throttle body on intake manifold (plenum). Tighten mounting bolts and nuts to specification. See TORQUE SPECIFICATIONS. After installing accelerator cable, hold exposed portion of cable at center and move cable up and down to ensure slight amount of play is available. Refill cooling system.

THROTTLE POSITION SENSOR (TPS)

Note. DO NOT remove throttle position sensor unless it has tested defective and is being replaced.

Remove air cleaner. Disconnect TPS mounting screws and remove TPS from throttle body. To install, reverse removal procedure. Tighten TPS mounting screws to specification. See TORQUE SPECIFICATIONS table.

Note. See ADJUSTMENTS article for throttle position sensor adjustment.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS