However, if a timing light is absolutely unavailable, you can attempt a *very rough* adjustment using the following *extremely unreliable* method:
WARNING: This method will likely result in suboptimal performance and potentially engine damage. Proceed with extreme caution.
1. Identify the distributor: Locate the distributor on your engine. It's the cylindrical component with a rotor and cap on top, usually near the front of the engine.
2. Find the timing mark: On the engine's harmonic balancer (the pulley at the front of the crankshaft), you should find a timing mark (often a notch or pointer). Consult your owner's manual or a repair manual to pinpoint its location and the degree markings.
3. Locate the distributor hold-down clamp: This will allow you to rotate the distributor.
4. Roughly set the engine to Top Dead Center (TDC) on the compression stroke of cylinder #1: This is the hardest part without a timing light. You'll need to manually turn the engine using a wrench on the crankshaft pulley. You'll be looking for the #1 cylinder to be at the top of its compression stroke. *This is incredibly difficult to determine accurately without tools.*
5. Visual inspection (extremely unreliable): With the engine at TDC (as best you can guess), observe the rotor position inside the distributor cap. It should point towards a specific position. Your owner's manual *might* give a rough indication, but this is unreliable without the proper tools and knowledge.
6. Minor distributor rotation: Loosen the distributor hold-down clamp slightly. You can then rotate the distributor slightly clockwise or counter-clockwise. *Start with very small increments (a fraction of a degree).*
7. Listen to the engine: As you rotate the distributor, listen to the engine's running. You're looking for a smooth idle. Too far advanced and the engine might ping (a high-pitched metallic sound). Too far retarded and the engine will run poorly and possibly misfire. This is highly subjective and unreliable.
8. Tighten the clamp: Once you find (by guesswork) a point where the engine seems to run most smoothly, tighten the distributor hold-down clamp.
Again, this method is highly unreliable. It's crucial to understand that even a small error in the timing can significantly affect engine performance, fuel economy, emissions, and longevity. Get a timing light; it's the only way to accurately set the ignition timing. Your local auto parts store might rent one. A repair manual specific to your Jeep CJ7 258 will also be invaluable.
