UCN-01, Fluorouracil, and Leucovorin in Treating Patients With Metastatic or Unresectable Solid Tumors

DISEASE CHARACTERISTICS: * Histologically confirmed solid tumor that is metastatic or unresectable and for which no standard curative or palliative measures exist or are effective * No brain metastases or primary CNS malignancy PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * Not specified Hematopoietic * Absolute neutrophil count at least 1,500/mm3 * Platelet count at least 100,000/mm3 Hepatic * Bilirubin no greater than 1.5 mg/dL * AST and ALT no greater than 3 times upper limit of normal Renal * Creatinine no greater than 1.5 mg/dL OR * Creatinine clearance at least 60 mL/min Cardiovascular * No known active coronary artery disease Pulmonary * No pulmonary dysfunction Other * HIV negative * No history of unusually severe and/or prolonged toxicity during prior therapy with fluorouracil (5-FU) or 5-FU prodrugs * No diabetes mellitus requiring insulin or oral hypoglycemic therapy * No ongoing or active infection requiring IV antibiotics * No other serious concurrent medical illness that would preclude study * No psychiatric illness or social situations that would preclude study * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy * At least 4 weeks since prior immunotherapy and recovered * No concurrent cytokines during the first course of therapy Chemotherapy * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered Endocrine therapy * No concurrent systemic corticosteroids Radiotherapy * At least 2 weeks since prior radiotherapy and recovered * No prior pulmonary or mediastinal radiation exceeding 40 Gy Surgery * Recovered from prior surgery Other * No other concurrent investigational agents * No concurrent cimetidine * No concurrent sorivudine or brivudine