Fuel System Issues:
* No fuel: Check the fuel tank level. Sounds obvious, but it's the easiest thing to rule out first.
* Fuel pump failure: The pump might be dead, weak, or not getting power. Listen carefully near the fuel tank for the hum of the pump when the key is turned to the "on" position (but not cranking). A mechanic can check fuel pressure.
* Clogged fuel filter: A restricted fuel filter can prevent sufficient fuel from reaching the engine.
* Fuel delivery issues: Problems with the fuel lines, injectors (if equipped), or carburetor (most likely on an '81) can prevent proper fuel delivery. A carburetor could be clogged, flooded, or have a malfunctioning float.
Ignition System Problems:
* Distributor cap and rotor: These wear out over time and can cause misfires or prevent the engine from starting. Look for cracks, corrosion, or worn contacts.
* Spark plugs and wires: Worn or fouled spark plugs or damaged wires can prevent a spark from reaching the cylinders. Inspect them for wear, damage, or fouling.
* Ignition coil: This component boosts the voltage to create the spark. A weak or faulty coil won't generate enough power.
* Ignition module/control unit: These control the timing and spark; a fault in this can prevent proper ignition.
* Cranking sensor/pickup coil (distributor-based ignition): This component signals the ignition module when the engine is turning, triggering the spark. A malfunctioning sensor prevents ignition.
Other Possibilities:
* Low battery voltage: While it's turning over, a weak battery might not provide enough power for the ignition system to function properly. Test the battery voltage.
* Starter issues (despite turning over): A starter motor can be engaging but not turning the engine over fast enough to ignite. Check for unusual sounds from the starter.
* Timing chain/belt: While less likely to prevent turning over entirely, a severely stretched or broken timing chain or belt will absolutely prevent the engine from running. But usually this would be accompanied by other sounds.
Troubleshooting Steps:
1. Check the basics: Fuel level, battery voltage (use a multimeter), and listen for the fuel pump.
2. Inspect the distributor cap and rotor: Look for cracks, corrosion, or wear.
3. Check spark plugs and wires: Inspect for damage, fouling, or cracks. You might even test them individually using a spark plug tester.
4. Listen to the engine: Are there any unusual noises when cranking?
5. Check for codes (if equipped): Some '81 models had rudimentary diagnostic systems.
Because there are so many potential issues, it's often best to consult a mechanic, especially if you're not comfortable working on older vehicles. They have the tools and experience to diagnose the problem accurately and efficiently. Starting with the simple checks can save you time and money, though.
