engine hesitation volvo xc70 Fuel pump and fuel filter was replaced 6 months ago

What is your question?

occurrs on extreme heat days in Las Vegas. Replaced fuel pump and filter 6 months ago. Drive belt may be due for replacement as mileage is at the recomended replacement threshold. Also I notice it only occurs when fuel level is at 1/2 a tank or below

What makes this problem better or worse?

worse when tank is half full

How long has your 2004 Volvo XC70 had this problem?

few weeks