88 Pontiac Firebird V6 2.8 liter
I bought a brand new belt last year and put it on then stored the car for the winter and now there is slack in the belt and the tensioner is already tight. Any ideas on how to tighten it? Thanks

Also my tach is going crazy and my oil pressure gets low when idling. Any Ideas?

 

adjust the slack out of your belt using the alt. bracket. as for the tach and such, prolly a bad wire somewhere ( loose connection )