I thought there is a way to do it (points distributor) with a test light attached to the distributor points lead by bringing #1 cylinder near top dead center on the compression stroke to the static ignition timing mark on the crankshaft. Then turning the distributor until the test light goes on (or is that off???) and that is the firing point? I did a Mallory dual point distributor like that (I think) back in the day.
MikeR
Found this from back in 2002, has a couple of other tips or methods on how to set ignition timing without a timing light. I have a Snap-On adjustable timing light that I've had for a long time but I always like stuff like this, MacGyver eh?
Gary T03-22-2002, 08:21 AM
There is a procedure for setting the ignition timing to the spec without a timing light. It requires a test light or a voltmeter. Carefully done, it's rather accurate, easily within one or two degrees.
First, set the point gap, or better yet, the dwell angle. If a dwell meter is available, that's definitely preferable to a gap measurement. Experience has shown me that in many cases the specified point gap doesn't always result in the specified dwell. Dwell angle is what you really want, point gap is an approximate way to achieve it.
You need to know which direction the distributor rotor rotates. A manual will tell you, or you can observe it by cranking the engine with the distributor cap off or by watching while doing the next step.
Bring the crankshaft to the timing spec. In other words, if the spec is 5 degrees before top dead center, you want the pointer at the 5 degree mark. It must be brought there in the direction of normal engine rotation (clockwise on the overwhelming majority of cars, but observe it to be certain). Rotating backwards to line the mark up brings in any timing chain slack and skews the synchronization between the crankshaft and the distributor (which is driven off the camshaft). If you pass the mark, you can go back a ways beyond it to "reset," but be sure the final motion is two inches or more of crank pulley circumference in the direction of normal rotation.
Loosen the distributor hold-down enough to be able to turn the disributor. Connect the test light or voltmeter to the coil negative terminal (which should connect directly to the points in the distributor), with its other end connected to ground. Turn the ignition switch on.
If the points are open, the test light will light up (or the voltmeter will read battery voltage). If the points are closed, the light will be off (voltmeter reads zero). DO NOT ALLOW THE POINTS TO REMAIN CLOSED WITH THE IGNITION ON ANY LONGER THAN NECESSARY. This burns points up in short order. Side note: generally you want to avoid having the ignition on with the engine not running. If the points happen to be closed, they will suffer. Use the accessory position or let the engine run.
If the light is on, turn the distributor in the direction of its rotor rotation until the light goes off. (If the light is off, presumably it's already where you want it.) Now turn the distributor in the OPPOSITE direction of its rotor rotation until the light comes on. Go back and forth a time or two to get the feel of it. You want the distributor to be at the exact point where the light just comes on when rotating it opposite from rotor rotation. Tighten the distributor hold-down. Done.
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cornflakes03-22-2002, 09:06 AM
Originally posted by Gary T
There is a procedure for setting the ignition timing to the spec without a timing light. It requires a test light or a voltmeter...Bingo.
If you don't have a ohmmeter, set the engine on the compression stroke, then remove the distributor cap and put some cellophane from a pack of cigarettes between the points. Pull gently on the cellophane as you rotate the engine towards top dead center. The cellophane will move when the points open, and this is where your timing is currently set.
You might also try turning the engine until you're at the timing mark, retarding the distributor and then turning the distributor until the cellophane pulls out, but you would probably want to check it again by turning the engine afterwards to make sure the timing is right.
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jsleek03-22-2002, 09:34 AM
I used the test light method, as suggested above, on my VW for a long time. I didn't even need the light, as I could hear a spark across the points as they opened. So set the timing mark by turning the engine (somehow), turn on the ignition, rotate the distributer to hear the spark.
