The banjo bolts that hold the fuel lines to the DeLorean's engine can sometimes sometimes leak. This article addresses some of these issues.
Use New Washers[]
When installing the banjo bolts, you should always use new washers, as the washers are designed to crush when the bolt is tightened. Reusing them can result in less crushing and an improper seal, which may result in fuel leaking from the connections.
Heating the Washers[]
The Ontario DeLorean Owners Club has an article by Stefan Diklich about fixing leaking fuel line connectors by specially prepping the washers on the banjo bolts. This involves heating the washers with a blowtorch and then quenching them in water, then mounting them in the engine while they are still warm. This method allows the washer to form around the bolt as it is tightened, ensuring a good seal. The article includes pictures for each step. That article also suggests that this method may work better than new washers.