Weird idle problems

I have a 96 Tacoma 2.4 two wheel drive with automatic tranny. Truck has almost 600k on it. It was developed a strange idle problem. Truck will start and drive perfect till about 50 miles into a trip and then it develops the rough idle while stopped. It will be rough for about 10sec then just die unless I shift to natural and keep the rpm up.
Just trying to pick some others brains out to see if they had the same problems. Trying to save some money on chasing the problem.

Thanks for the help

 

IF....your engine has solid lifters, like my 93, it could be the pushrods are due for an adjustment. The valve pushrods might have just enough gap to start and run, but when they reach a certain temperature or driving distance, they expand enough to omit that gap and the valves cannot close. Thus, the engine stalls. Get that checked and adjusted as soon as possible or you can burn your valves and seats.