My 156 has that problem as we speak.........am able to get it started by spraying petrol into the throttle body(stop laughing!). Get some petrol in a spray bottle, remove the large black plastic throttle tube where it meets throttle body and spray(squirting is better) some petrol into the body. Try and twist the flap in the throttle body so that you can squirt the petrol in. Connect the plastic tube back on (don't fasten it just yet as you will probably need to repeat this a couple of times). Try starting it as soon as you've squirted the petrol in.........may take a few attempts.
The local roadside assist guys tried this and got the car going. It was able to then start/stop most of the day, but next morning same problem appeared and was again able to get it going only with the above process.
Fuel pump activates, fuses are ok.
Car is going to the mechanics in a couple of days and will update the outcome.