1997 Ford Escort - stalls in 90 degree or hotter weather

We have a 1997 Ford Escort 2L single overhead cam. The car itself has 134k miles on it. The engine was just replaced last week, the engine itself has about 90k miles on it. It's an automatic, FWD.

2 months ago, the rod bearing went out which is why the engine was replaced. At the same time, they replaced the serpentine belt.

We've had this stalling problem with the car for as long as we've owned it. The car starts and runs great in cold weather but in extreme heat (90+), the car starts but after awhile will stall while driving it. Before we replaced the engine, you could let the car sit for 5-15mins and it would start back up and run for a little while longer and possibly repeat the process. Sometimes, you had to let it sit longer.

Today is the first day it's been driven all day since getting it back from having the engine replaced. It was between 90 and 95 outside. It ran fine until I was on my way home around 4pm and then died. I let it sit for a few minutes and it would start back up but it won't stay running. After an hour, it still would not stay running. I ended up leaving it where it died and will try again later tonight when the sun goes down and it's cooler outside.

I unplugged the MAF and it didn't help.