Engine will not start unless feed tank pump number 4 on

[tangottt]

Aircraft Version

Stable

Build info

"built": "2024-11-09T16:34:34+00:00",
    "ref": "refs/tags/v0.12.3",
    "sha": "7c0bb7fee6051b07edd3435d923b7acf1cec2945",
    "actor": "FoxtrotSierra6829",
    "event_name": "manual",
    "pretty_release_name": "stable/v0.12.3",
    "version": "a380x-v0.12.3-rel.7c0bb7f"
}

Describe the bug

1) engine will not start within reasonable time period until at least 1(main/stby) fuel pump at ALL feed tank is on. With addition on issue #2841 , the N2 & N3 hardly increase but do eventually engine become "avail" after 39minutes.

2) after engine shut down, N2 will remains on 0.7 and will not return to 0

Expected behavior

1) able to start the powerplant as normal with normal increasing N1,N2,N3 speed

2) N2 returns to 0 eventually

Steps to reproduce

1. start up aircraft as normal but not turning on fuel pump
2. by adjusting the sim rate, issue 1 should be able to reproduced
3. turn on main FEED TKS 1,2,3,4 pump on
4. engine would start at normal pace
5. after all engine become avail and verified responds to throttle input, switch engine masters to "off"
6. with aids of simrate, the N2 value would remain at 0.7 while N1.N3 returns 0

References (optional)

No response

Additional info (optional)

No response

Discord Username (optional)

tangotea

[donstim]

This should be re-classifed as a feature request. It is not a bug. It simply has not been implemented yet.

[tangottt]

hi, but engine should operate with its respective pump on, ie: eng1+2 can start normally with tank1&2. but current engine behaviour is not, ie: engine 1 can not successfully start without tank pump 3,4(on right wing) on

[donstim]

Ah, yes, that is definitely an issue. The engines do feed off their respective feed tanks and can be crossfed from any other feed tank once they are started, but this is not working properly for engine start. It appears that the feed tank 4 pumps must be on for any of the engines to start. The other feed tank pumps need not be on, the crossfeed valves don't need to be open for engines 1 to 3 to start from the feed tank 4 fuel pumps being on, and the fuel is drawn equally from all 4 feed tanks (even with engine 4 not running).

Could you either change the title on this issue to match or open a new issue (bug) with this description?