have a 2002 v6 that will start when cold. after it warms up and you try to crank, it starts to backfire and runs rough if it starts. are the chains as bad on the v6 as they are on the v8? car sat up for awhile. got 129k on the clock. check engine light doesn't come on and no codes show in scanner. has new plugs

 

You are mistaken as the chains are not bad on any of the engines.

Chances are you have an air leak or bad coils so use Search to read up on those as you'll also find tests & fixes.

 

seems like i have read a couple hundred threads here where the tensioners have gone south and wiped out a few motors. don't think a vaccum leak would kept the check light from working or scanner from picking anything up. used starting fluid at all connections and no change in rpms. car had been hot at one time before i got it. has new thermostat housing and overflow bottle replaced

 

The tensioners went bad on the early engines, not the chains.

Sounds like a vacuum leak to me too.

 

I'm done on this one.