Hyundai Coupes/Sedans 1986-1993 Repair Guide

Diagnosis and Testing

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See Figures 1 and 2



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Fig. Fig. 1: Ignition system troubleshooting-all models



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Fig. Fig. 2: Ignition system component view-Elantra

SERVICE PRECAUTIONS





Make sure all connectors are fastened securely. A poor connection can cause an extremely high surge voltage in the coil and condenser and result in damage to integrated circuits.
 
Keep all parts and harnesses dry during service.
 
Before attempting to remove any parts, turn OFF the ignition switch and disconnect the battery ground cable.
 
Always use a 12 volt battery as a power source.
 
Do not attempt to disconnect the battery cables with the engine running.
 
Do not depress the accelerator pedal when starting.
 
Do not rev up the engine immediately after starting or just prior to shutdown.
 
If a battery cable is disconnected, the memory will return to the ROM (programmed) values. Engine operation may vary slightly, but this is not an indication of a problem. Do not replace parts because of a slight variation.
 
If installing a 2-way or CB radio, keep the antenna as far as possible away from the electronic control unit. Keep the antenna feeder line at least 8 in. away from the ECU harness and do not let the 2 run parallel for a long distance. Be sure to ground the radio to the vehicle body.
 

SECONDARY SPARK TEST



See Figures 3, 4, 5 and 6



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Fig. Fig. 3: This spark tester looks just like a spark plug, attach the clip to ground and crank the engine to check for spark



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Fig. Fig. 4: This spark tester has an adjustable air-gap for measuring spark strength and testing different voltage ignition systems



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Fig. Fig. 5: Attach the clip to ground and crank the engine to check for spark



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Fig. Fig. 6: This spark tester is the easiest to use just place it on a plug wire and the spark voltage is detected and the bulb on the top will flash with each pulse

The best way to perform this procedure is to use a spark tester (available at most automotive parts stores). Three types of spark testers are commonly available. The Neon Bulb type is connected to the spark plug wire and flashes with each ignition pulse. The Air Gap type must be adjusted to the individual spark plug gap specified for the engine. The last type of spark plug tester looks like a spark plug with a grounding clip on the side, but there is no side electrode for the spark to jump to. The last two types of testers allows the user to not only detect the presence of spark, but also the intensity (orange/yellow is weak, blue is strong).

  1. Disconnect a spark plug wire at the spark plug end.
  2.  
  3. Connect the plug wire to the spark tester and ground the tester to an appropriate location on the engine.
  4.  
  5. Crank the engine and check for spark at the tester.
  6.  
  7. If spark exists at the tester, the ignition system is functioning properly.
  8.  
  9. If spark does not exist at the spark plug wire, perform diagnosis of the ignition system using individual component diagnosis procedures.
  10.  

Cylinder Drop Test

See Figures 7, 8 and 9



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Fig. Fig. 7: These pliers are insulated and help protect the user from shock as well as the plug wires from being damaged



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Fig. Fig. 8: To perform the cylinder drop test, remove one wire at a time and ...



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Fig. Fig. 9: ... note the idle speed and idle characteristics of the engine. the cylinder(s) with the least drop is the non-contributing cylinder(s)

The cylinder drop test is performed when an engine misfire is evident. This test helps determine which cylinder is not contributing the proper power. The easiest way to perform this test is to remove the plug wires one at a time from the cylinders with the engine running.

  1. Place the transaxle in P , engage the emergency brake, and start the engine and let it idle.
  2.  
  3. Using a spark plug wire removing tool, preferably, the plier type, carefully remove the boot from one of the cylinders.
  4.  


WARNING
Make sure your body is free from touching any part of the car which is metal. The secondary voltage in the ignition system is high and although it cannot kill you, it will shock you and it does hurt.

  1. The engine will sputter, run worse, and possibly nearly stall. If this happens reinstall the plug wire and move to the next cylinder. If the engine runs no differently, or the difference is minimal, shut the engine off and inspect the spark plug wire, spark plug, and if necessary, perform component diagnostics as covered in this section. Perform the test on all cylinders to verify the which cylinders are suspect.
  2.  

IGNITION COIL



See Figure 10

Testing
EXCEL WITH FEEDBACK CARBURETOR


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Fig. Fig. 10: Checking the pick-up coil on the 1986-89 Excel

  1. Using a suitable volt/ohmmeter, measure the resistance. An open or short circuited coil should be replaced. The standard resistance values are as follows:
    1. Primary coil resistance-1.2 ohms
    2.  
    3. Secondary coil resistance-13.7 kilo-ohms
    4.  
    5. External resistor resistance-1.35 ohms
    6.  

  2.  
  3. Check the resin portion for cracks. If there are any cracks present, replace it.
  4.  
  5. Check for any fluid (oil) leaks. If there are any leaks present, replace it.
  6.  

SCOUPE, SONATA AND EXCEL WITH MPI
  1. Using a suitable volt/ohmmeter, measure the resistance. An open or short circuited coil should be replaced. The standard resistance values are as follows:
    1. Primary coil resistance-0.72-0.88 ohms
    2.  
    3. Secondary coil resistance-10.9-13.3 kilo-ohms
    4.  

  2.  
  3. Check the resin portion for cracks. If there are any cracks present, replace it.
  4.  
  5. Check for any fluid (oil) leaks. If there are any leaks present, replace it.
  6.  

ELANTRA

See Figure 11 and 12

  1. Using a suitable volt/ohmmeter, measure the primary and secondary resistances. An open or short circuited coil should be replaced. The standard resistance values are as follows:
  2.  



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Fig. Fig. 11: Measuring the secondary ignition coil resistance-Elantra



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Fig. Fig. 12: Measuring the primary ignition coil resistance-Elantra

  1. Primary coil resistance-0.77-0.95 ohms. Measure resistance between connector terminals 3 and 1, the coils at the No.1 and No.4 cylinder sides of the ignition coil, and between terminals 3 and 2, the coils at the No.2 and No.3 cylinder sides.
  2.  
  3. Secondary coil resistance-10.3-13.9 kilo-ohms. Measure the resistance between the high voltage terminal for the No.1 and No.4 cylinders and between the high voltage terminals for the No.2 and No.3 cylinders.
  4.  

When measuring the resistance of the secondary coil, disconnect the ignition coil connector.

  1. Check the resin portion for cracks. If there are any cracks present, replace it.
  2.  
  3. Check for any fluid (oil) leaks. If there are any leaks present, replace it.
  4.  

CONTROL UNIT



Testing
1986-89 EXCEL ONLY

See Figure 13

The control unit is internally mounted (in the distributor). Connect the igniter unit, battery, lamp or ohmmeter as shown in the illustration. Apply signal voltage. If the lamp lights or ohms are read when voltage is applied, and goes out or reads 0 ohms when the voltage signal is removed, the igniter may be considered good.



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Fig. Fig. 13: Test hook up for control unit checking-1986-89 Excel

Only the switching section of the control unit is checked with this test. Even if the unit tests as good, it could still be defective.

RELUCTOR GAP



Adjustment

See Figure 14

1986-89 EXCEL ONLY

The reluctor gap is adjustable on the Hitachi Electric distributor used on the Excel. While service is not required as a part of normal maintenance, if you have worked on the distributor or if you suspect the reluctor gap might be incorrect because of ignition problems, you can check and adjust it.

  1. Get a feeler gauge of non-magnetic material (brass, plastic or wood) of 0.8mm thickness. Remove the distributor cap and rotor.
  2.  
  3. Rotate the engine (you can use a large socket wrench on the bolt that attaches the front pulley) until one of the prongs of the rotor is directly across from the igniter pickup.
  4.  
  5. Insert or attempt to insert the feeler gauge between the prong and pickup. If the gap is correct, there will be a very slight drag. If the gauge fits loosely or cannot be inserted, loosen both mounting screws and then (if necessary widen the gap) insert the gauge. Slowly close the gap by pivoting the igniter assembly on the left screw and rotating it at the right side, where it's slotted. When the gauge is just touching, tighten first the right side screw and then the screw on the left. Recheck the gap and re-adjust as necessary. Reinstall the cap and rotor.
  6.  



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Fig. Fig. 14: Reluctor gap adjustment-1986-89 Excel

POWER TRANSISTOR



Testing

See Figure 15

SCOUPE, SONATA AND EXCEL WITH MPI
  1. Connect an analog type ohmmeter across terminals 2 and 3 of the power transistor.
  2.  
  3. There should be no continuity.
  4.  
  5. Connect the negative terminal of a 3 volt battery to terminal 2 and the positive terminal to terminal 1 of the power transistor. The ohmmeter should show continuity.
  6.  



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Fig. Fig. 15: Checking the power transistor-Sonata and Excel with MPI

  1. Replace the power transistor, if there is a malfunction.
  2.  

ELANTRA
  1. Check the power transistor for coil No.1 and No.4 as follows:
    1. Connect the negative lead of a 1.5 volt battery source to terminal 3 of the power transistor; then check for continuity between terminal 5 and terminal 3 when the terminal 4 and the positive terminal are connected.
    2.  
    3. Continuity should exist when terminal 4 is connected. Continuity should not exist when terminal 4 is disconnected.
    4.  

  2.  
  3. Check the power transistor for coil No.2 and No.3 as follows:
    1. Connect the negative lead of a 1.5 volt battery source to terminal 3 of the power transistor; then check for continuity between terminal 1 and terminal 3 when the terminal 2 and the positive terminal are connected.
    2.  
    3. Continuity should exist when terminal 2 is connected. Continuity should not exist when terminal 2 is disconnected.
    4.  

  4.  
  5. If the problem is still evident after tests are completed, replace the power transistor.
  6.  

 
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