Liquid fuel isnt working

[THIS IS ME IDIOT]

any time i activate my liquid fuel engines they activate but dont take in fuel or give thrust, i have them set up right beacuse they worked before.

[Rene]

As written in the FAQ:

Q: My rocket will not leave the launch pad, what can I do?
A: Throttle up (the SHIFT key)

Solid fuel rockets can only be off or on, liquids can have any throttle up to 100%, but 0% does nothing for you.

[THIS IS ME IDIOT]

that just makes it spark and then do nothing

[Proteus]

Also, of course, you have to get the right fuel.
There are 2 types of fuel tanks ... the one with oxidizer, the other one without ...
the fuel without oxidizer only works with jet engines, not with rocket engines


Another problem that migh arise is a broken connection between the fuel tanks and the engine as soon as gravity kicks in ... such a thing often happens if too much weight rests on too few engines (while the rocket stands on the launchpad)

[Bodkins(UK)]

As rene said-- Have you pressed shift to throttle up? and are the engines set up in the correct staging?

[THIS IS ME IDIOT]

nope still the same thing happening

[THIS IS ME IDIOT]

no to the weight just trying with pod, fuel and engine right now

[THIS IS ME IDIOT]

ok works for space ship but not for jet?

[Rene]

Liquid fuel engines require oxidizer. Regular rocket engines have oxidizers in their tanks. Jet engines require intake air. Put some intakes on your plane.

Solved.

[Trehek]

jet engines require an air intake instead of oxidizer.

[THIS IS ME IDIOT]

Do intakes have to be on the fuel?

[ChillestBro]

Some parts, depending on how you built your rocket, denies fuel crossfeeding, aka won't feed fuel from one side of the craft to the other without manually pumping the fuel towards the other tanks; Most likely you have a part between the fuel tanks and the engines that is cutting off the flow of fuel, causing flame-out.

To check this right-click the engines misfiring and the status will tell you LIQUID FUEL DEPRIVED for any issues with fuel flow, as well as the fuel bar next to the staged engines being empty. To fix this without rebuilding the rocket, attach fuel lines from the tanks with the fuel to either a part that does feed fuel to the engines or directly to the engines themselves, you should get fuel.

For future reference when you right-click an item in the VAB/SPB, it will give you all sorts of information on the part, and within one of the menus if it states "No fuel crossfeed available" in orange text, that part will only act as a structural piece and not feed fuel.

EDIT: For air-breathing engines, an atmosphere with Oxygen must be present and intakes must be on the aircraft, but these intakes don't follow fuel rules, so anywhere is fine.

[THIS IS ME IDIOT]

thx working now

[Trehek]

Also remember that availability of intake air is reduced at higher altitude. Extra intakes will allow you to gain extra altitude before you'll suffer flame outs. The ability to fly higher without switching engines to rocket mode is also beneficial because rocket mode expends much more fuel.

If you're building planes, here's a great GUIDE[forum.kerbalspaceprogram.com] to help you get started.

[SpitfireBALA]

Mine seems to be working fine.