I have a 2007 escalade Ext, with 257,000 miles on it. I was having an issue a couple of months ago where it would stall as I come to a stop after driving about 20 to 25 miles. After about a 30 - 45 wait it would start and run like nothing was wrong. I thought it was a fuel pump issue, so I had the pump replaced (AC DELCO) about two months ago. Since replaced I put about 1,800 miles on the new pump and last week it stalled out on me again. Waited about an hour until the tow truck came got home and it cranked right up. I was about to purchase a new set of fuel injectors but then read about the relay causing issues. I tested the old relay with a multi meter, but it is not showing issues where I read it should if it was bad. Can anyone help if you have experienced this issue??!!

What relay you working with? We need to narrow down where the problem is. When it stalls try using ether or carb cleaner and see if it will hit on it. If so, we know it'* fuel related. If not, we need to look at the ignition side.
Try the test and see what we get.

A couple of months ago . . . like in cold weather?

Right after it stalls, what would happen if you tried to start it?

Was this a guess, or was there low fuel pressure or somesuch diagnosed?

Has the weather been warmer since then?

I suggest you don't go replacing stuff without diagnosing it first. Grab a cheap code scanner and see if it has anything stored.

Is the check engine light on?

The original relay for the fuel pump was a Tyco 9831. I replaced it with an AC Delco 8430. I will try that to see. I plan on taking it on a test run this weekend to see what happens.

I'm in Louisiana so two months ago it was cold one day, cool the next and then hot. It seemed to run extremely better than normal when it was cooler. But I did notice at low rpms such as going through a school zone my Stabil Trac light would come on then go off after about 30 seconds or so. The fuel pump was a guess because right after it stalled it would try to crank but wouldn't turn over. I had to wait about 30-45 min for the truck to cool down then it would crank right up with no hesitation. I have a decent scanner, but I had someone come over and plug a better one up to the truck but because it was starting and running nothing showed to be wrong.

It didn't crank or is it a crank and no start? Fuel pump will not stop cranking. Turn over and cranking are the same. Turn over does not mean it starts just that it cranks.
It communicates with the vehicle but no codes? A scanner can read live data. Do you have a code reader or scanner?
You need to learn the terminology.

So . . . no check engine light and no codes?

Probably not the fuel pump relay as that becomes irrelevant after there'* oil pressure (because it is running).