What is the name of your state? Illinois
Is there a limitation on the time a Judgment creditor has to file a citation to discover assets on a third party?
No, not if the judgment is still valid.
Rule 277. Supplementary Proceedings
(a) When Proceeding May be Commenced and Against Whom; Subsequent Proceeding Against Same Party. A supplementary proceeding authorized by section 2--1402 of the Code of Civil
Procedure may be commenced at any time with respect to a judgment which is subject to enforcement. The proceeding may be against the judgment debtor or any third party the judgment creditor believes has property of or is indebted to the judgment debtor. If there has been a prior supplementary proceeding with respect to the same judgment against the party, whether he is the judgment debtor or a third party, no further proceeding shall be commenced against him except by leave of court. The leave may be granted upon ex parte motion of the judgment creditor, but only upon a finding of the court, based upon affidavit of the judgment creditor or some other person, having personal knowledge of the facts, (1) that there is reason to believe the party against whom the proceeding is sought to be commenced has property or income the creditor is entitled to reach, or, if a third party, is indebted to the judgment debtor, (2) that the existence of the property, income or indebtedness was not known to the judgment creditor during the pendency of any prior supplementary proceeding, and (3) that the additional supplementary proceeding is sought in good faith to discover assets and not to harass the judgment debtor or third party.