PEPSI is an abbreviation of
"Pay Every Penny to Save Israel"?
The first Pepsi-Cola Company was formed in 1902, and the name "Pepsi"
was patented in 1903 - way before Israel was created.
The story about its name is as follows:
In 1898 Caleb D. Bradham, a small town pharmacist looked for a
name that would better describe his formula which he was selling
locally under the name "Brad's Drink." He bought the name
"Pep Kola" from a local competitor and changed it to Pepsi-Cola.(*)
So PEPSI isn't an abbreviation, it doesn't stand for anything.
(* pepsi website)