Problems with liquid engines

[xxXHonestJohnXxx]

Just playing Kerbal for a few days and are starting to get  the hang of it to put stuff into orbit arround Kerbal. The problem is getting back because the rocket engines wont start to get out of orbit.
 In my case i am using an LV-909 as i saw in a youtube video from  Scott Manley where he uses the same rocket to get back to Kerbal. Have checked everything but the engine wont start only a puff kind of sound and thats it. There is enough electricity and fuel and oxidizer is at 100%. Also tested other kind of rockets but nothing works, what am i doing wrong -.-

[FullMetalMachinist]

17 minutes ago, xxXHonestJohnXxx said:

the engine wont start only a puff kind of sound and thats it.

This bit makes it sound like you might be pressing space bar to try and get the engine to fire again. Correct? If so, don't do that, it stages away your engine and won't be part of your ship anymore. Instead press left shift to throttle up, or press z to go full throttle. 

If that's not the problem you're having, a screenshot will be helpful. 

[Ty Tan Tu]

I doesn't sound like it because you say you hear a puff sound, but are you sure it is not some staging issue? After you get rid of a stage you need to hit the space bar again to activate the next stage

[xxXHonestJohnXxx]

I feel like an complete idiot, thanks for your reply Tay Tan Tu, the problem was to simple. needed to press the shift key, the throttle was with crtl at zero i feel such a dumb ass.

[DD_bwest]

if you can, right click on the engine.   the second one from the bottom will be either activate or deactivate engine,  make sure its activated, and if not click the bottom to make sure it is.   this is the manual way to fire an engine without it being in your staging,  but it should be in your staging anyways.  if you cant get it to work, try taking a screenshot with the part window open so we can have a look to see whats going on

[Ty Tan Tu]

A screen shot would help. It just occurred to me that if it is an unmanned craft, it is possible you lost communication with it and have limited control. Just as a general tip, you can 'fix' that from the alt+F12 menu. Click on 'Input Locks' and then the "Clear Input Locks' bar.

[Snark]

9 hours ago, xxXHonestJohnXxx said:

I feel like an complete idiot, thanks for your reply Tay Tan Tu, the problem was to simple. needed to press the shift key, the throttle was with crtl at zero i feel such a dumb ass.

Don't feel too bad, we've all been there!

Quick show of hands from anyone who's never done anything "dumb" in KSP?

<crickets>

...yah, thought not. 

[Ultimate Steve]

6 minutes ago, Snark said:

Don't feel too bad, we've all been there!

The first Kerbal I killed was when I attached boosters to one of my early rockets. But I didn't move the camera. And I had put on one booster instead of three by mistake...

Also, on my first Kerballed Minmus landing, I almost kicked my lander over.

[Kerbal Fried Chicken]

I had a similar problem when the lander I detached from my transfer craft had a different control point then anticipated. "wait!. I said hold retro! why is my AP climbing??"  we've all been there.