In a large saucepan, combine peaches, onion, pepper, cilantro, garlic, cumin, vinegar, and lime zest. Stir together pectin and 1/4 cup sugar. Bring to a boil, and stir in remaining 3 1/2 cups sugar. Boil for 1 minute, stirring constantly. Remove from heat, and stir for 5 minutes.
Pour peach salsa into prepared jars, leaving 1/4 inch air space. Seal, and process in a boiling water bath for 15 minutes.