Symptoms of a Bad Distributor:
* Engine won't start: This is a major symptom. The distributor is responsible for supplying the spark, so without it, the engine won't fire.
* Engine cranks but won't start (or runs rough and dies): The engine turns over, but fails to ignite. This suggests a problem with the ignition system, and the distributor is a prime suspect.
* Misfiring/rough idle: The engine runs poorly, hesitates, or misfires. This indicates that the spark isn't being delivered consistently or to the correct cylinder at the right time.
* Stalling: The engine dies unexpectedly, especially when idling or under load.
* Hard starting (especially when hot or cold): It takes excessive cranking to start the engine.
* Poor fuel economy: A misfiring engine, caused by a bad distributor, burns more fuel.
* Check Engine Light (CEL): A malfunctioning distributor can trigger the CEL. Get the code read to pinpoint the problem. However, the CEL might not directly point to the distributor, but rather a related sensor or system issue.
Testing the Distributor (Requires some mechanical ability and safety precautions):
Important Safety Note: Work on the ignition system should only be done when the ignition is OFF and the battery disconnected. High voltage is present even after the ignition is turned off.
Direct testing of the distributor itself is tricky without specialized tools. However, you can check related components to isolate the problem:
1. Check the distributor cap and rotor: Inspect for cracks, burns, corrosion, or worn contacts. Replace if damaged. A simple visual inspection is a good first step.
2. Check the ignition coil: A faulty ignition coil can also mimic distributor problems. Test the coil with a multimeter (if you have one) to check its resistance.
3. Check the spark plugs and wires: Worn or damaged spark plugs and wires will prevent a good spark from reaching the cylinders even if the distributor is fine. Inspect them for wear and tear, and consider replacing them if necessary. A simple visual inspection is a good first step.
4. Check the pickup coil (or crankshaft position sensor, if equipped): The pickup coil in the distributor (or the crankshaft position sensor if your S10 Blazer has electronic ignition) senses the engine's rotational position and triggers the spark. Testing this requires a multimeter and technical knowledge. A faulty pickup coil can mimic distributor problems.
5. Listen for the distributor sound: With the ignition on, but not cranking the engine, you might hear a faint clicking sound from the distributor if it is operating. However, this is not a conclusive test.
If you're not comfortable working on your vehicle's electrical system, take it to a qualified mechanic. Misdiagnosing and incorrectly attempting to fix the distributor can lead to more damage or injury. Replacing the distributor can be a bit involved depending on your comfort level and familiarity with the vehicle.
Remember that many of the symptoms listed above can be caused by other components. Systematic checking of the ignition system is key to pinpoint the true culprit.
