Troubleshooting issues (Hyundai Elantra XD)

When troubleshooting an engine, start by checking the operation and inspecting the main systems. If the engine is running poorly, has erratic idle speed or poor acceleration, check the following major systems:

1. Electrical power supply

• Battery
• Burn-through jumper
• Fuse box

2. Connections to "mass"

3. Fuel supply

• Fuel line
• Fuel filter
• Fuel pump

4. Ignition system

• Spark plug
• High voltage wires
• Ignition coil

5. Emission control system

• Crankcase ventilation system
• Vacuum leak

6. Others

• Setting the ignition timing
• Idle speed

MFI system malfunctions are often caused by poor connections in the wiring harness connectors. Therefore, check that all connectors are securely connected.