Persons seeking injunctive relief typically have to show some sense of urgency in order for the court to act. If you were aware of circumstances for a while and did nothing about it, the court will be inclined to deny your request for injunctive relief. In another words, if you unreasonably delay in asserting your claim, particularly where the delay has prejudiced the other party, the defense of "laches" is applicable. The period of "laches" may be much shorter than the legal statute of limitations. The court in each case will determine whether the delay was sufficiently long and sufficiently unreasonable for "laches" to be operable.
"Unclean hands" is another defense to injunctive and other equitable relief. If you yourself have been guilty of inequitable or wrongful conduct with respect to the particular matter at issue, the court will likely not issue an injunction. The "unclean hands" arises out of the particular matter you are suing on and courts are not supposed to examine your conduct in other matters or question your general character in dealing fairly. (But judges are human.)