There is a Timing pin that will fall into place when cylinder #1 is on top dead center. The problem is that pin can wear and no longer engage. If thats the case you'll have to use another method. I usually find when both valves are closed on the #1 cylinder, That is roughly TDC on compression stroke. Knowing that you are on compression stroke is key. Then adjust the exhaust valve down about 2 turns, rotate the motor in one direction until the piston contacts the valve and you can't rotate further (don't try to force it, you don't want to bend anything). Mark the harmonic balancer. Now rotate the engine the other direction until you contact the valve again, and mark the balancer. I usually mark on the right side(drivers side) of the position sensor, so you mark from the same point both times. These marks represnt TDC on the exhaust stroke either side of TDC compression stroke. Directly in between these two marks is top dead center on the compression stroke. Be very careful in determining what directly in the center is.
This way has worked for me, but if you can use the timing pin, that is the best most accurate way to do it. Good luck. let us know if you need any clarification.
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