air4655

Is there anything I can do to lower the engine idle on my 1990 LS 400. I am not a mechanic... don't even know where to look to find something to adjust.

I just bought my 1991 LS400, picked it up in Houston, and drove it to Denver. The prior owner had taken it in for low idling, and the mechanic set it too high. It is fine when it is in gear.. about 1000 rpm, but if I put it in neutral or park, it shoots up to 1300. Is there anything I can do to lower it without having to take it in to a shop or the dealer. Other than that, it runs great thanks