You really do not need timing light to do ignition timing. In fact, mine is collecting dust... here is how I do the job quickly and without a mess or getting those timing light wires caught in the fan blades. It's great if you need to time in the field!  It works on my fuel Injected 258 CJ7 (and before it was fuel injected), my Carbed 84 Bronco II, and a host of other vehicles from points ignition to modern EFI systems.   Be careful, making sure in step #1 you are on the compression stroke, or you are going to be 180 degrees out of sync. 1. Pull the Cylinder #1spark plug. 2. Put you finger in Cylinder # 1 spark plug hole. 3. Manually rotate the engine until you feel compression building up. 4. Look at the timing marks and put the marks at about 6 to 8 degrees BDTC. 5. Unlock the distributor hold down clamp. 6. Lightly lock down the distributor so it can be rotated by hand. 7. Install the spark plug to #1 spark plug wire. 8. Ground the plug so you can see the electrode. 9. Turn the ignition to Run. 10. Quickly rotate the distributor and to obtain a spark when the rotor sees plug #1. 11. Narrow down the rotation as much as possible. 12. When as narrow as possible, lock down the distributor. On some fuel injected vehicles you can also listen for an injector to open and close...so you don't have to pull the plug!  It works great! 13. Put everything back together together. Now engine is statically timed. You are at home plate in the ballpark... not out in the field. You may need to finesse the adjustment a bit when the engine starts, but you are now correctly timed!   If a timing problem exists now, it's narrowed down to: 1. Distributor Advance Mechanism (or Computer). 2. Engine Vacuum. 3. Timing gears and Chain.