To convey politeness, I would use the conditional tense. For example, instead of "I want to" I would use the phrase " I would like to" If you want to ask him for his support, something like " I would be grateful for you support on this project" would be polite, and would likely generate a response, even if it's not a question. To be a bit more direct, you could say something like "Would you be willing to support this project? I would very much appreciate your support." But I agree with Michelle; it would be easier to formulate a response to a more specific project and type of support

Hi Iris, what do you mean by "support"? Do you want funds for your project? Do you need him/her to talk to someone about it? I would ask specifically for what you want him/her to do.