Engine chugging

Engine light does not come on. I bought the vehicle three months ago. I have no idea if it has had a recent tune-up. Before I bought the Jeep I drove it for about five miles with no issues. Ran smooth when I pushed it. Had no hesitation, changed gears smoothly.
I stopped at a stop sign did not idle rough. Pulled out onto main highway with no hesitation.
So I bought it. I left the car lot and was on main highway everything still okay.
I was coming into a heavy construction zone less than two miles from car lot. Lot of cars and trucks front and behind me and all of a sudden the Jeep started losing power as if it had gone into neutral gear. Vehicle started getting slower and slower in the middle of heavy traffic. I pushed on gas peddle and engine revved up but vehicle was slowing to a crawl. I just made it past the construction area and was able to pull off onto side of road at which time the engine sputtered and quit.
I turned the key back on, vehicle started again. Traveled about two miles, same thing happened. Jeep slowed to a crawl and engine shut off. I started vehicle up and got less than half mile same thing happened again. I waited about two minutes and turned key on and vehicle started up drove rest of way home with no further problem.
Since then I have had no more issues with vehicle stalling out. Just the chugging sound when stopped or at slow speed when accelerating.