20V? so you have two marks yeah. crank and cam gear.
sometimes when I do them I will pull the pin and it will move what I wanted. If this is happening to you...line up the crank mark and if the cam mark is off(which I'm assuming it is), then ask yourself if moving it ONE tooth will be what you want. If it will...line up your marks NOT for on pretension but what you want after tension.
I know that all sounds crazy but it always works for me.
And you might be good really. I don't know what method you are using to find TDC with the crank(mark, flywheel, screwdriver in the cylinder) but you usually have some play to work with. That's why I say...can it be made better by moving one tooth. The answer is usually pretty obvious. If it can't...roll with it...if it can...move a tooth.