1. Ignition Switch:
* Check the ignition switch itself: Ensure it's providing power when the key is turned to the "start" and "run" positions. A multimeter can test for power at the switch's output wires.
2. Battery and Connections:
* Battery voltage: A weak or dead battery won't provide enough power for the ignition system. Check the battery voltage with a multimeter. It should be around 12.6V when fully charged.
* Clean battery terminals and cables: Corrosion can severely impede current flow. Clean them thoroughly with a wire brush and baking soda solution. Ensure all connections are tight.
3. Ignition Coil:
* Visual inspection: Look for any obvious damage to the coil itself, such as cracks or burns.
* Resistance test: Use a multimeter to check the resistance of the primary and secondary windings of the coil. These values should match the specifications in your vehicle's repair manual. A shorted or open coil will prevent spark.
* Check for power at the coil: With the ignition on, test for battery voltage at the positive (+) terminal of the coil.
4. Ignition Control Module (ICM): These cars often have an ICM.
* Visual inspection: Check for any signs of damage or overheating.
* Replacement: ICMs are notorious for failure and are often the culprit in no-spark situations. Replacing it is often the most effective solution if the coil and other components test good.
5. Distributor:
* Rotor: The distributor rotor distributes high voltage to the spark plug wires. Check for cracks or burns. It should spin freely and make good contact with the cap.
* Distributor Cap: Inspect the cap for cracks, carbon tracking, or corrosion on the contact points.
* Spark Plug Wires: Check for damage, fraying, or cracks in the insulation. Replace if necessary. A bad wire can cause a misfire or no spark in a specific cylinder.
* Distributor Pick-up Coil (or Magnetic Pickup): This component in the distributor senses the position of the crankshaft and triggers the ignition. Testing requires an oscilloscope or a specialized tool.
6. Crankshaft Position Sensor (CKP Sensor): Some models might use a CKP sensor instead of relying solely on the distributor. Check this sensor if there are no signs of problem in other components.
7. Spark Plugs:
* Check the gap: Incorrect spark plug gap can impede or prevent sparking. Check the gap using a feeler gauge and adjust as needed (refer to your owner's manual or repair manual).
* Inspect for fouling or damage: Soiled plugs can prevent sparking. Clean or replace as necessary.
Troubleshooting Steps:
1. Start with the easiest checks (battery, connections, visual inspections).
2. Check for power at the coil.
3. Test the ignition coil's resistance.
4. Inspect and/or replace the distributor cap and rotor.
5. Check spark plug wires.
6. Investigate the ICM if other components are good.
7. Consider the CKP sensor if it's applicable.
Important Note: A repair manual specific to your 1983 Oldsmobile Delta 88 with the 307 V8 is highly recommended. It will provide wiring diagrams, component specifications, and troubleshooting procedures specific to your vehicle. These diagrams are critical for correctly testing and tracing power and signal flows. Without a manual, you're essentially working blind. The information above is general and may not entirely cover your specific car's setup.
