Phaeton W12 does not start/does not start/does not start/does not start/does not start/does not start/does not start/does not start/does not start/does not start/does not start/does not start/does not start again

Good afternoon, I have a problem with a Phaeton W12 MKB: BAN Bj:2003 The error is as follows: The engine starts and goes out after 2 sec. again. If the accelerator pedal is kicked during the start the engine stays running as long as it is actuated, if you let it go the engine goes off. The exhaust gas smells very strongly of gasoline and the engine also has malfunctions. Furthermore, the airbag SG can not be reached. I hope someone can help me. MfG Kaleut1988