I know "I have no time." is correct.
I have no much time.
But as to "I have no much time." to mean "not enough time", the sentence seems to have self-contradiction in a sense.
Is the sentence correct?
No, it is not correct.
"no much" is never correct, instead use "not much."
That is not much time.
Not much later, he left.
When using 'not', in general move the negative to before the verb:
I went not very far. (awkward) -->
I did not go very far. (correct)
So, the solution:
I have no much time. (wrong) -->
I have not much time. (awkward) -->
I do not have much time. (correct)
I don't have much time. (correct)