you may need to cap off each end of fuel lines then on one end pump a bit of air in to pressurize the line, harbor freight has some hand vacuum pumps that will work for this they have a gauge on them as well so you can see if its one of the hardlines leaking and if so you can take soapy water in a spray bottle and soak down the lines and you should find the hole pretty quick.

89 2 dr turbo diesel
89/88 "Backwoods sas"