My 90 Accura has around 160,000 miles on it and it ldles a little rough and starts a little hard sometimes and I was going to run one of those fuel additive cleaners through it just to see if it helped since Im pretty sure nobody ever bothered to do it before.

Is that stuff safe for these engines? Especially such a high mileage engine... I dont want to make things worse, and is there a brand that would be better to use than others?