Most likely rotted fuel lines.I had a customer come to my shop and told me he wanted his fuel lines replaced and he knew which ones.I ask him how he knew and he said he went to an exhaust shop for a free exhaust inspection and they showed him what lines were leaking.He told me hew knew he had nothing wrong with his exhaust,he just wanted to find the fuel leak which he didn't mention to the mechanics.I'm not saying to do that,but it was kind of funny because it didn't cost him anything for a diagnoses.They gave him an estimate for the exhaust,but he said he couldn't afford it yet and would let them know.Almost forgot,his was a 1995 Ford Explorer.