OBJECTIVES: I. Determine the maximum tolerated dose of weekly irinotecan in combination with weekly fluorouracil and cisplatin in patients with locally advanced or metastatic solid tumors. II. Determine the dose limiting toxicity for this combination regimen in this patient population. III. Establish a recommended phase II dose for this combination regimen in these patients. IV. Evaluate the safety and tolerability of this regimen in these patients. V. Observe any responses to this combination chemotherapy in these patients. VI. Measure in pretreatment biopsies levels of expression of thymidylate synthase, topoisomerase I, ERCC-1, thymidine phosphorylase, and dihydropyrimidine dehydrogenase as correlates to response or resistance to this combination chemotherapy in these patients.