Filing Injunction on Sale for Reinbursment of down payment
The answer will partially depend on whether the money provided by the grandparents was a gift or a loan. In order to obtain an injunction, a party needs to show that money damages can't compensate for harm that will occur without an injunction. Often, a temporary restraining order is issued when a divorce is filed, to preserve the status quo and prevent the other party from selling or wasting marital assets that likely won't be able to be recovered later. However, this is granted to the party filing the divorce, rather than creditors of a spouse. Generally, a lender will file a complaint for breach of contract to recover the money owed, and if successful and the judgment isn't paid, the unpaid judgment may be used to place a lien of the judgment debtor's property. When a lien is placed on property, it is generally more difficult to sell until the lien is paid.
Utah is an equitable division state. This means that the property will not necessarily be divided equally and it will be a matter of subjective determination for the court to divide the property, based on all the facts and circumstances involved. Generally, gifts made to a spouse are considered separate property, but if used for the common benefit or both spouses, it may become marital property. If the downpayments were a loan, it will be a matter of determination of fairness, taking all considerations into account, for the court to decide how the parties are to be responsible for paying debts owed. I suggest you contact a local attorney who can review all the facts and documents involved.