95 k-2500 overfueling smell

[Cornfield creations]

My mom drives a 95 k-2500 w/ a tbi 454 auto. It seems lately that it is overfueling. The exhaust smells good when it is up to temp, but otherwise it smells like raw gas. It has no cat on it. Is this because of the closed loop on the fuel system until it reaches operating temp? Or because it is really overfueling?

If it is overfueling is it adjustable? I haven't played much on the tbi's.

Thanks guys!