Timing belt slapping against cover

[TMB]

I just finished changing my timing belt yesterday and was getting a strange noise. I thought the cam lobes were hitting the valve cover but as it turns out I didn't tighten the tensioneor enough. I tightened it and the noise went away for the most part but I still get it a little under acceleration. So I pulled the cop timing cover off and when I accelerate the belt is slapping the cover. I'm assuming I have to pull the belt back off and get it another tooth tighter?

[ganda1f]

Do your timing marks align as they should? Crank at TDC on cyl1 compression stroke and the hole in camshaft sprocket aligned with the notch on the bearing cap? In that case no, do not move the belt, you will put your engine out of time.
Loosen the tensioner pulley, check the free length of the spring. If that checks out all right, make sure that the pulley can move freely on the pivot stud. Use a wrench on the crankshaft bolt and rotate the engine clockwise slowly, so that you put tension on the front side of the t-belt (the one not touching the tensioner). Now, as soon as the camshaft starts to rotate, tighten the tensioner pulley. This way the belt will have the proper tension applied by the spring.

If the timing marks do not align then yes, you need to move the belt to set timing correct. Then tighten the tensioner as described above.