vapour lock is the problem due to low fuel pressure ,this can be caused by a partially clogged filter or a leaky fuel accumalator . to rectify replace the fuel filter and the fuel accumalator next to it.

Ocaasionally the fuel -pump relay does act up and cause idling shut down ,restarts immediately ; rectify by replacing fuel relay or by resoldering the cold solder joints carefully. Hopefully this will help

mak
300se W126
300SEL W109