Problem With '99 Alero

I am a newbie here and thank you for letting me join in. I have a problem with a '99 Alero I bought for my grandaughter. It is a 99 2 door with a 2.4 TC engine.I got it about 6 months ago and no real problems so far till last weekend. After an overnight sit and I start it up it runs at about 1000 rpm's and then starts to rev down to about 700-750 and then the rough idle starts.Oh it is terrible. I have replaced the plugs, the plastic tower above the plugs, checked for jumped time, coil packs and idle sensor. What have I missed?Please help. If this is posted elsewhere here please direct me to the post. Thanks BlazinMike:banghead::banghead:

What the heck does this crap have to do with my Alero?

What the heck does this crap have to do with my Alero?

Spammer and banned.

Got the timing cover off and right off noticed it was 1 tooth off. One plastic guide was broke.Tensioner looked worn. Replaced the guides and tensioner.Reset the correct timing. All is fine. Running like a top.