FiTech EFI system

You might just be better off to replace that single line with new rubber hose. probably plugged somewhere from age. Yes EFI forever.
Ken
X1000. Lets all remember that with 40 year old rubber and metal lines on these cars, it's 100% within the realm of possibility that reusing an existing line w/o checking it for flow, can lead to issues. Mud dobber wasps are real SOB's...