OBJECTIVES: I. Identify the toxicity associated with increasing doses of monoclonal antibody F19 (BIBH-1) administered weekly by intravenous infusion in patients with unresectable, advanced or metastatic fibroblast activation protein-positive colorectal cancer. II. Determine the dose limiting toxicity and maximum tolerated dose of this drug in these patients. III. Measure induction titers of human anti-human antibody to BIBH-1 and correlate immunologic-related clinical effects. IV. Determine the pharmacokinetics, biodistribution, and imaging characteristics of increasing intravenous doses of the drug. V. Document tumor responses in this patient population.