OBJECTIVES: I. Determine the maximum tolerated dose and secondary organ toxicity of high dose yttrium Y 90 monoclonal antibody MN-14 (90Y-hMN-14) plus autologous peripheral blood stem cell rescue in patients with metastatic or recurrent colorectal or pancreatic cancer. II. Compare the tumor to organ dose ratio between 90Y-hMN-14 and iodine 131 monoclonal antibody MN-14 (131I-MN-14) in these patients. III. Determine the antitumor effects with myeloablative doses of 90Y-hMN-14. IV. Evaluate the immunogenicity of 90Y-hMN-14 in these patients.