BMW gas odor

I have a 1987 525 BMW which has had a significant gas odor for some time. No one has been able to find the cause–replaced the gas tank and other parts and done a smoke test. The car is in great shape otherwise and I would like to keep it but won’t if I don’t fix this problem. Any suggestions?

How about replacing every fuel line in the engine compartment?

I have seen injectors leak externally.

I had to do a intake re-seal on a mid-90’s V-12 BMW, I had to replace every fuel line under the hood, they were so stiff I had to cut them off.

I also had a 87 528e BMW great car,good mileage,lots of room good fit

thanks for the tips–worried that replacing ALL lines is very $ and may not do the trick. How much would you estimate?