Engine Controls - Adjustments Hyundai Sonata II

ENGINE COMPRESSION

Ensure engine is at normal operating temperature, battery is fully charged and starter is operating properly. Remove all spark plugs and hold throttle valve wide open. Crank engine at least 6 engine revolutions per cylinder to determine engine compression. Engine cranking speed should be 250-400 RPM.

COMPRESSION SPECIFICATIONS

VALVE CLEARANCE

Note. Sonata models use hydraulic lash adjusters. No adjustments are required.

EXCEL

1. Ensure head bolts are properly tightened before adjusting valves. Ensure engine is at normal operating temperature. Rotate crankshaft clockwise to position cylinder No. 1 on TDC of compression stroke.
2. Adjust intake valves on cylinders No. 1 and 2, and exhaust valves on cylinders No. 1 and 3. Rotate crankshaft clockwise 360 degrees to position cylinders No. 4 on TDC of compression stroke.
3. Adjust intake valves on cylinders No. 3 and 4, and exhaust valves on cylinders No. 2 and 4. See «VALVE CLEARANCE SPECIFICATIONS»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments) table.

VALVE CLEARANCE SPECIFICATIONS (1)

CHECKING HYDRAULIC LASH ADJUSTERS

1. Remove valve cover. Press where rocker arm contacts lash adjuster at the very top. If adjuster is normal, it will feel very hard.
2. If hydraulic lash adjuster moves easily downward, it is faulty and must be replaced.
3. If hydraulic lash adjuster feels soft or spongy, air has probably entered hydraulic lash adjuster. If this occurs, check engine oil level. If engine oil level is okay, check oil screen and oil screen gasket for damage.
4. After repairing cause of air leak, warm engine to operating temperature. If there is abnormal noise at idle, bleed the hydraulic adjusters.
5. To bleed hydraulic adjusters, slowly increase engine speed to 3000 RPM and back to idle over approximately 60 seconds. Repeat this several times. This will help remove air from hydraulic lash adjusters. If there is still abnormal noise, replace noisy hydraulic lash adjusters.

IGNITION TIMING ADJUSTMENT

1. Ensure vehicle is at normal operating temperature, all accessories are off and transmission is in Park or Neutral. Front wheels must be in straight-ahead position and curb idle speed is set to specification.
2. Ground ignition timing adjustment connector Light Green/Red wire. (Scheme 1)& (Scheme 2). Check ignition basic timing. See the «IGNITION TIMING»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments) table. Disconnect ground wire on ignition timing adjustment connector. Check ignition actual timing. Refer to the «IGNITION TIMING»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments) table.
3. If timing is incorrect, loosen distributor hold-down nut and turn distributor until timing is correct. On 1.5L and 2.4L engines, ignition timing will be advanced if distributor is turned to the left and retarded if turned to the right.
4. On 3.0L engines, ignition timing will be advanced if distributor is turned to the right and retarded if turned to the left. After adjustment, tighten hold-down nut. Ensure distributor does not move when tightening hold-down nut.

Scheme 1

Scheme 2

IGNITION TIMING (Degrees BTDC @ RPM)

Idle Speed Check

1. Ensure coolant temperature is 176-203°F (80-95°C). Turn all accessories off. DO NOT check curb idle speed while cooling fan is operating. On power steering-equipped vehicles, ensure steering wheel and front wheels are in straight-ahead position.
2. Install a tachometer and timing light, or connect a Multi-Use Tester (09391-33000) to diagnostic connector in the fuse box. Operate engine at curb idle speed of 600-800 RPM (650-850 RPM on 2.4L Sonata). Ensure basic engine timing is 3-7 degrees BTDC.
3. Operate engine for more than 5 seconds at 2000-3000 RPM, then run engine at idle for 2 minutes. Check idling RPM. If a multi-use tester is used, press Code No. 22 and read idling RPM. If idle is not within specification, adjust Idle Speed Control (ISC) and Throttle Position Sensor (TPS). See «IDLE SPEED CONTROL»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments) and «THROTTLE POSITION SENSOR (TPS) ADJUSTMENT»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments__throttle-position-sensor-tps-adjustment) in this article.

Scheme 3

Excel & Sonata 4-Cylinder

1. Engine coolant temperature should be 176-203°F (80-95°C). Turn all accessories off. DO NOT check curb idle speed while cooling fan is operating. Place transmission in Neutral or Park. On power steering-equipped vehicles, ensure steering wheel and front wheels are in straight-ahead position.
2. Loosen accelerator cable. Connect a tachometer. Connect a digital voltmeter between ground terminal (Black wire) and signal terminal (Light Green wire) of Motor Position Sensor (MPS) connector. Backprobe MPS connector. DO NOT disconnect MPS connector.
3. Turn ignition switch to ON position for at least 15 seconds. This sets ISC motor in idle position. Check voltage at MPS, output voltage should be.9 volt. Turn ignition switch to LOCK position. Disconnect ISC servo motor connector. Put ISC motor in retracted position.
4. Open throttle valve by hand 2-3 times and allow to return with a snap each time. Loosen fixed Speed Adjusting Screw (SAS). (Scheme 3)
5. Start engine and run at idle. Check engine speed and motor position sensor output voltage. Engine speed should be 600-800 RPM (650-850 RPM Sonata 2.4L). If engine speed is not within specification, adjust idle speed with ISC adjusting screw. (Scheme 3)
6. Tighten fixed speed adjusting screw until RPM increases. Loosen screw until RPM ceases to drop (touch point), then loosen screw an additional 1/2 turn. Check Throttle Position Sensor (TPS) adjustment. See «THROTTLE POSITION SENSOR (TPS) ADJUSTMENT»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments__throttle-position-sensor-tps-adjustment) in this article.
7. Turn ignition off and adjust accelerator cable. Connect ISC motor connector. Disconnect harness and voltmeter.
8. Start engine and ensure idle speed is 600-800 RPM (650-850 RPM Sonata 2.4L). Turn ignition off. Disconnect battery for 15 seconds to erase diagnostic memory. Reconnect battery. Readjust accelerator cable. See «ACCELERATOR CABLE PLAY SPECIFICATION»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments) table.

ACCELERATOR CABLE PLAY SPECIFICATION

Sonata V6

1. Engine coolant temperature should be 176-203°F (80-95°C). Turn all accessories off. DO NOT check curb idle speed while cooling fan is operating. Place transmission in Neutral or Park. On power steering-equipped vehicles, ensure steering wheel and front wheels are in straight-ahead position.
2. Loosen accelerator cable. Connect a tachometer. Ground ignition timing adjusting connector. (Scheme 2) Start engine and check ignition timing. Adjust if necessary. See «IGNITION TIMING ADJUSTMENT»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments__ignition-timing-adjustment) under IGNITION TIMING in this article.
3. Turn ignition switch to OFF position. Ground self-diagnostic check terminal. (Scheme 4) Run engine at 2000-3000 RPM for at least 5 seconds. Allow engine to run at idle speed for 2 minutes. Engine speed should be 600-800 RPM. If engine speed is not within specification, adjust using speed adjusting screw, located on side of throttle body.
4. If idle speed is higher than specification, even with speed adjusting screw fully closed, check if fixed speed adjusting screw (idle switch) has been moved. Adjust as required.
5. Turn ignition off. Remove ground from self-diagnostic check terminal. Disconnect tachometer. Disconnect battery for 15 seconds to erase diagnostic memory. Reconnect battery.
6. Readjust accelerator cable. See «ACCELERATOR CABLE PLAY SPECIFICATION»(/hyundai/sonata/ii-1988-1993/remont/adjustments/#engine-controls-adjustments) table. Start engine and run at idle for at least 5 minutes. Check engine idle speed.

Scheme 4

IDLE MIXTURE

Note. Mixture adjustment is computer controlled and nonadjustable.

THROTTLE POSITION SENSOR (TPS) ADJUSTMENT

1. Loosen throttle cable. With ignition off, connect a digital voltmeter between terminals No. 1 (Black wire) and No. 2 (Light Green/Yellow wire) of Throttle Position Sensor (TPS) connector. DO NOT disconnect TPS connector, backprobe through rear of connector.
2. Turn ignition on, but DO NOT start engine. Check TPS voltage. If reading is not .48-.52 volt, adjust TPS until correct voltage is obtained. Turn ignition off and disconnect digital voltmeter. Adjust throttle cable. Disconnect vehicle battery for 15 seconds or more. Start engine and check idle speed.

See also:
• VALVE CLEARANCE SPECIFICATIONS
• THROTTLE POSITION SENSOR (TPS) ADJUSTMENT
• IGNITION TIMING ADJUSTMENT