'vil ha' means specifically 'want to have' and is followed by a noun e.g. 'Jeg vil ha kaffe' = 'I want [to have] coffee' 'vil' is followed by a verb e.g. 'Jeg vil spise' = 'I want to eat' or (as in this case) a preposition with the verb implied 'Jeg vil tilbake' = 'I want to go back'
Ok so according the the verbix.com norwegian section, future tense can be used using vil. I will go = Jeg vil gå I know that Jeg skal gå also means I will/shall go and I have heard that using vil also means with intent, i.e. I want to go but surely this translation should also include I will go back?
In this case the only verb in the Norwegian sentence is 'vil', so it's the main verb in the sentence rather than an auxiliary verb to 'go'. On its own 'å ville' means 'to want/to wish', so this sentence can translate to variations of "I want(/wish) to go back(/return)".
If the sentence had been "Jeg vil dra(/reise/gå) tilbake", then yes, it could have been translated in that way as well. Saying "Jeg kommer til å dra(/reise/gå) tilbake" would still be a more common and less ambiguous way of expressing it though. "Jeg vil returnere" = "I will(/want to) return" is yet another way to express the same thing.
It can mean "I want to go back", "I will go back", and it could also mean "I shall go back", but the last one depends on the context. So you are right. Edit: All of them depends on the context I guess, so if you wanted to be sure that people understand you if you want to say "I want to go back" (You want to, but you aren't saying whether you are going to or not) you should say "Jeg skulle ønsket at jeg kunne gå tilbake" = "I should have wanted that I could go back" (Horrible english, I know). If you say this, people will think that there is somehing that makes it hard, or that something is holding you back from going back or something though.
After reading all the explanations, I still don't get why there is no second verb after "vil", I find this sentence missing something. I know that "vil" means "want", so this sentence sounds to me like "I want back". I feel the right way to say "i want to go back" would be something like "jeg vil gå tilbake". Or is the movement verb "gå" implied in "vil"? Thank you in advance.
Not a native, but here are my 2 cents anyway: I think the movement is implied in "tilbake". It's a compound word: til + bake, with "til" meaning "to" and "bake" meaning "back".
You are right that "I want back" doesn't really sound like good english, but you shouldn't make the mistake of trying to translate word for word. English and Norwegian are two different languages, so what may sound off in one language is perfectly fine in the other. That being said, the literal (and very off sounding) translation would be "I want to-back".