Engine loss @ throttle down

[denism3s]

I have had power loss on my 350lx everglades on multiple occasions. It can be one two or all three engines. Occurs only at throttle down. We have triple 300 Suzuki`s.
It does not happen underway , no loose connections, batteries OK. We do have dedicated batteries to port and starboard engines, center and house are connected.

[boats.net]

May need to have the idle control checked to see if working properly and check for any fault codes.

[denism3s]

the codes have been check by 2 Suzuki certified techs. none found. Will idle all day long, no problems found with idle controls either. Tis happens only on slowing down. It makes no difference if it is slow or sudden.