You do not need IRB approval before submitting a funding proposal, you can list your IRB status as pending and, with most federal agencies (NIH, NSF, Dept. of Education). Check the specific agency's guidelines on human subjects research.
While you do not need to have IRB approval before you submit your proposal, it is best not to delay your IRB application too long since it can hold up the funding decision, and If your grant is ready to be funded but you haven't yet received IRB approval, most funding agencies won't release funds until approval is verified. When you do submit your IRB application for a funded or soon-to-be-funded study, make sure the research described in your funding proposal matches your IRB application (including matching titles), since the IRB must ensure the research it approves aligns with what the sponsor is supporting.