Symetrical Fuel Lines NOT Flowing Equally to Jet

[inigma]

I have three tanks:

1 Jet Fuel

2 Rocket Fuel

I have two jet engines:

1 Basic Jet Engine

1 Turbo Jet Engine

The Setup:

- I have symetrical fuel lines from the Jet Fuel tank to the Rocket Fuel tanks.

- I also have the flow in reverse with symetrical fuel lines from the Rocket Fuel tanks back to the Jet Fuel tank.

This is to balance out fuel usage, and it works well.

JFT

// \\

RFT RFT

\ /

BJE

TJE

The Problem:

When I attempt to run symetrical fuel lines from the Rocket Fuel tanks into the Basic Jet Engine and TurboJet Engine stack to feed those engines, the fuel usage from the rocket fuel tanks is not equal. One tank gets emptied of its fuel before the other causing craft imbalance. I'm not at my comp, so I can't remember but only one of those engines is the culprit, the other engine balance fine.

Hypothesis:

Apparently symetrical fuel lines from the rocket tanks are not flowing symetrically, and instead only flow from one rocket tank. Also the one rocket fuel tank that does empty is not getting replenished from the Jet Fuel Tank via its connected fuel line. It's as if the affected jet engine only will pull in from one rocket tank, and the fuel line from the Jet Fuel Tank is not flowing to the emptying Rocket Fuel Tank. Is this working as designed? Anyone else run into this? I've rebuilt my craft from scratch several times and each time it does this.

Edited December 11, 2013 by inigma

[Vanamonde]

I also have the flow in reverse with symetrical fuel lines from the Rocket Fuel tanks back to the Jet Fuel tank.

If you have a loop anywhere in your fuel flow, weird things will happen.

[MircoMars]

you can only feed in one direction. to avoid burnouts, connect a fuelline from your last full tank directly to the engines.

[Murph]

I'm not certain, but I believe that alternate paths in the middle of the fuel flow can be a problem (and loops to be avoided completely, as already mentioned above). So, 1-into-2-into-1 type things can be an issue. I know from experience that 2-into-1-into-2 works ok, at least in some cases, but more complex can be problematic.

The best advice I can offer is to try to keep fuel lines to an absolute minimum, if possible, and as simple as possible. Do a manual fuel transfer once you reach orbit, if there's a weight balance problem for descent. There are also some good fuel management mods out there, to make life more pleasant when pumping fuel around for balance  TAC Fuel Balancer is the one I'd recommend.

[xtremespino]

I have had this problem before, I just re-placed the fuel lines until it worked.

[thereaverofdarkness]

I've had symmetrical fuel loops work and fail. It might be your ship design, it might just need to be redone. Can we see pics of it?

[Kasuha]

Scan for fuel starts at the engine. It goes from the engine through pipe to the RFT, then through the pipe to the JFT, then through the backwards pipe to LFT. There it ends because it ran out of parts it did not yet scan. And it starts drawing the fuel from the tank where it ended (or switch RFT and LFT, it depends on order in which you placed your pipes where the search goes first).

Install pipes from RFT and LFT to JFT, then one pipe from JFT to the engine and it will work.

[inigma]

I simplified the fuel flow and simply connected my Rocket Fuel Tanks to my Jet Fuel Tank, and connected the Jet Fuel Tank to all engines. Works beautifully. The suggestion to keep a singular flow and avoid loops fixed it.