I'm doing some maint work on my 84 coupe and found the timing belt a little slack. The belt is fairly new so it must have been put on not very tight. Timing marks look ok, just a slack belt. The lower timing cover is on and will stay on. I can and have loosened the tensioner pulley but it won't move (is it supposed to?).

 

Its self tensioning, you have no pretensioned it. you have to losen it, then rotate the center, and then tighten it while holding. You have old car, so you have to use something like a special tool, or a nail and a screw driver. you put the nail into the hole, and use the screw driver and the hex key for leverage.

 

I don't think we're on the same page. With the lower cover in place, only the smallest bit of the tensioner pulley is exposed. The only bolt that is there is a small 10mm hexhead bolt. It is not eccentric so I can't rotate it to provide more tension. It "looks" like it may slide in a groove but who knows. I got tired of screwing with it and put the cover back on. The AC line was in the way making it a pain in the butt.

 

This is a 10v I5, btw.