Owner's Problem Description
The owner reports that their 2000 Mitsubishi Mirage DE with a 1.5L engine won't start. Initially, the vehicle started after swapping the spark plug wires on the distributor cap, but it only ran for about an hour before stalling again. After refueling, it failed to start altogether. Previous actions included checking the wiring and confirming the correct routing. The owner has tools and is working with a friend who has a shop.
Professional Technical Analysis
The 2000 Mitsubishi Mirage DE features a 1.5L engine and is experiencing a no-start condition following previous intermittent starting issues. The vehicle was initially responsive after swapping the spark plug wires on the distributor cap, indicating a possible previous misfiring condition. The problem re-emerged after brief operation, suggesting underlying issues such as improper electrical connections or timing problems. Presently, the engine shows good compression at approximately 115 PSI, which is within acceptable limits but may indicate other timing-related issues if the timing belt has skipped a tooth. The initial symptoms of stalling after a short runtime could be linked to wiring issues leading to intermittent electrical faults affecting the ignition system. Additionally, the owner has removed the timing cover for inspection, which may provide insight into the timing alignment. Any irregularities in the timing belt alignment could result in a no-start condition, and it’s critical to check the firing order of the spark plugs to avoid further complications. This vehicle is known to experience ignition-related issues, particularly when the distributor cap and rotor are not in optimal condition. If the timing or firing order is incorrect, the engine will not start, presenting a significant diagnostic priority. The current condition requires a thorough inspection of the ignition system, including the distributor, spark plug wires, and timing components, to ensure all systems are operating correctly.
Possible Causes
Most common causes (ordered by frequency):
- Ignition System Misfire: The spark plug wires were incorrectly routed, which caused misfiring and erratic starting conditions. Re-checking the firing order and ensuring that the wires are routed according to the manufacturer specifications is critical. The correct firing order for the 1.5L engine is typically 1-3-4-2, and any deviation can lead to non-start conditions. Ensure that the distributor cap and rotor are in good condition as well, as wear can lead to poor electrical contact. - Engine initially started after wire swap but stalled shortly after, indicating potential wiring issues or misfiring.
- Timing Belt Issue: With compression measured at 115 PSI, the timing belt may have skipped a tooth, affecting valve timing. This can lead to a no-start condition as the valves may not open and close properly in relation to the piston stroke. Inspecting the timing belt for wear or misalignment is necessary, as failure to address this could lead to engine damage. - Good compression indicates possible timing issues if the timing belt is misaligned; checking timing marks is essential.
- Distributor or Rotor Fault: A faulty distributor cap or rotor can lead to inconsistent spark delivery to the cylinders. Inspect the distributor for cracks, corrosion, or carbon tracking which can impede performance. The rotor should be replaced if any wear is evident, as this can cause starting issues. - If the engine does not start after checking the wiring, inspect the distributor cap for signs of wear or damage.
- Electrical Connection Issues: Bad connections in the ignition system can prevent the engine from receiving adequate voltage. Inspect all connectors and grounds associated with the ignition system, ensuring they are clean and secure. Corrosion or loose connections can lead to voltage drops that cause misfires or no starts. - Check for corrosion or looseness in the terminal connections of the ignition system.
Diagnostic Steps
Professional Diagnosis Process
Follow these systematic steps to accurately diagnose the issue. Each step builds on the previous one to ensure accurate diagnosis.
- STEP 1 - Initial Visual Inspection: Begin with a thorough visual inspection of the engine bay, focusing on the distributor cap, spark plug wires, and timing belt. Look for any signs of wear, damage, or improper routing of the wires. Ensure that the ignition components are correctly connected and free of corrosion. A good practice is to refer to the vehicle's service manual for correct wiring diagrams and specifications.
- STEP 2 - Compression Testing: Since the compression reading is at 115 PSI, perform a compression test on all cylinders to confirm that the timing belt is not causing an issue. If compression readings are significantly different across cylinders, it may indicate a problem with the timing belt alignment or valve issues. This test requires a compression tester, which can be rented from auto parts stores.
- STEP 3 - Electrical System Check: Utilize a multimeter to check the voltage at the ignition coil and ensure it is receiving adequate power (typically 12V with the key in the 'on' position). Check for continuity in the spark plug wires and inspect the distributor cap for any signs of wear or carbon tracking that may indicate electrical faults. This step is critical to ensure all electrical components are functioning as intended.
- STEP 4 - Timing Inspection: With the timing cover removed, visually inspect the timing belt for any signs of wear or misalignment. Ensure that the timing marks on the crankshaft and camshaft align properly. Also, check if the timing belt has maintained proper tension. If any discrepancies are found, further adjustment or replacement may be necessary to prevent engine damage.
