This article covers the diagnostic process used to locate a fault within a 2002 Hyundai Accent. The complaint is the engine seems to “miss” during acceleration.
Step 1. Talk to the customer Retrieve as much information as possible though don’t allow them to set you in any particular direction. You are the technician not the owner.
Step 2. Assess the maintenance schedule If the vehicle maintenance schedule is not complete, a fault can often be rectified by performing the maintenance. Services and Tune ups are maintenance procedures, diagnosing a fault is another step further. This vehicle was 7000kms over due for its last service.
Step 3. Drive the vehicle to confirm the fault is occurring This is where your experience driving vehicles with faults come in, use all your senses. With practice you can “feel” when an ignition misfire occurs, take note if it feels like just one cylinder or more. Another clue is if it is a regular miss or seems to be random occurring on all cylinders, usually your ears will give you this information. While accelerating this vehicle seemed to miss on one cylinder regularly, the beat from the exhaust plus the vibration. through the driveline were the best indicators.
Step 4. Set a diagnostic plan Focusing on the Ignition system, start at the spark plug end or the coil primary end and work from one end to the other in a logical order. In this example I’ll start at the spark plugs.