Starts but wont stay running on 2002 Buick Rendezvous

My car starts fine but cuts off when it reaches normal running temp. Then it wont start again until I let the car cool down for about 45 minutes. Could this be a fuel problem? The car did sit for about 5 months because the fuel pump needed to be replace and I did not have the money to get it fixed. I have had it back from the shop for about a month when this problem started happening.

Asked by for the 2002 Buick Rendezvous