I found the best way to determine TDC for each piston in turn was with a piece of coathanger wire, marked with a small piece of tape. You stick it into the sparkplug hole resting on the top of the piston until it comes up and just starts to go down again. Then put the tape on the wire right at the edge of the sparkplug hole.

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1986 560SL
2002 Toyota Camry
1993 Lexus