link g4x storm disconnecting from laptop on start up

im run link g4x storm with autronic 500r cdi on ls2 also have two link can widebands. and the minute the engine starts it disconnect from lap top. i tried 4 differnt laptops. all do exactly same thing. the second the engine dies it reconects. I am using the standard #1 port via usb. any ideas ?

CDI can be pretty tough on USB comms. The wiring needs to have all noise reduction precautions taken, Autronic's documentation is sparse in this subject matter but M&W manuals have some good general tips so suggest reading one or their manuals too. CDI needs to be grounded separately to ECU, generally direct to battery negative, definitely not to engine where ecu is grounded. Shielded twisted pair cable for the coils and for the CDI power supply, spiral wound plug leads and preferably resistor spark plugs. Keep plug gap small - typically 0.6mm with CDI.

Ferrite beads on both ends of the USB cable can help too.