timing belt to loose then to tight

[racer951y]

I went to check my timing belt today on my 90 944 S2 and when i got the tool ready and checked (with Porsche tool #9201) I got a reading of .5!! So I looked around wondering my my engine had not died yet and saw that both the bolts for my adjuster had back off a little and the adjuster was just another wheel holding the belt on. so when i readjusted the belt I was getting either way high of a reading (around 8) or to lower of a reading (2 or 1.5) I could not get the 2.7 the manual says to get for a belt with over 3K kilos on it (mine is around 15,000 miles) I got it to a 5 and called it good. Is that to tight? or will all be fine?