The 2 valves in the lift pump can fail. If you have more than 1/2 a tank it wont drain back as the return line will be below the fuel level in the tank. Unless you have an air leak in your fuel system.
If you park the car facing down hill over night & the problem is not there the next morning then it strongly suggests an air leak.
Have you changed your filters recently?
Are you only using regular diesel?

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving