Fuel Tech FT550 disconected when engine running

is there anyone ever solve this problem?

without engine run, everything perfect, connection etc,

when we try cranking and then engine running, laptop to ecu got disconnected.

try to rev up and then let go the throttle, ecu got connected for 3 seconds, then disconnected again/

Hey Victor, you won't believe me, but that happened to me in a client car and i was crazy trying to find the problem. At the end were the spark plugs, i don't know why, but i replace the plugs for another ones (another brand) and the problem was gone after that.

Have a look to that just to see.

Cheers.

Victor, that seems a lot like a bad connection somewhere - it's PITA but you may need to check every connections' pins and sockets are still in place and weren't disloged and pushed back - this can cause intermittent drop outs. But before that, you may be able to narrow it down by having the laptop connected, engine ignition on, etc, and wiggling the wiring to see if there's a section that caused the connection to drop out, including both ends of the laptop connection if hard-wired.

William, might have been non-resistor plugs initially, replaced by resistor type? The latter will normally produce less electro-magnetic interference, and if the connection is susceptable?