Restless motor run + Lambda lamp

Hello, I have a new problem for you. It has already occurred several times. The first time about 2 months ago. The last time today. It always started so that it starts to run and jerk while driving (with a petrol engine you would say Ignition drop-outs). If you then stay still he jerks strongly, runs extremely rough goes out or runs as long as the Lambda lamp lights up. As soon as the lamp lights up, it runs normally, it also goes after some This has happened 3 times so far, but today in the morning he sawed up and down in the idle in the stand and ran round. Between the first times there were a few weeks, but now this problem occurs more frequently, also that he only runs in the short term, but then stops again. If you leave out the codes now you get EFI-714 Fuel Shut Off Valve signal and EFI-715 Fuel Regulation. If someone has an idea about what to do. I would be happy to have an answer. Mfg Valentin