My 1997 jeep grand cherokee starts o.k i have no check engine light on, but every now and then the idle will go down for a few seconds and sudden acceleration will occur. this happens regardless of the car being cold or warm. i have replaced the map sensor, tps, and idle control sensor, and pcm. still does it.

https://www.google.com/search?rlz=1C1CHBF_enUS757US757&sxsrf=ALeKk01pb5OD-dO7NbzwvZN4ZADFalsVlw%3A1615749844954&ei=1GJOYI_fOY6m_Qacp4GYAQ&q=1997+Jeep+Grand+Cherokee+starts+and+dies&oq=1997+Jeep+Grand+Cherokee+starts+and+dies&gs_lcp=Cgdnd3Mtd2l6EAMyBggAEBYQHjoHCCMQsAMQJzoHCAAQRxCwAzoCCAA6CAgAEBYQChAeOggIIRAWEB0QHlDNNFitV2DeWWgBcAJ4AIABdIgB3wqSAQQxMy4zmAEAoAEBqgEHZ3dzLXdpesgBCcABAQ&sclient=gws-wiz&ved=0ahUKEwiPmbecwbDvAhUOU98KHZxTABMQ4dUDCA0&uact=5

Sounds like a few issues. The check engine light should come on when you turn the key to "ON" without attempting to start it. If it doesn't, the bulb could be bad and that would mean removing the instrument cluster to change the bulb.
The rough idle issue could be a partially stuck open EGR valve. Remove the valve and clean it good. While you have it out make sure the diaphragm moves freely. Replace the valve if you can't clean it or if it doesn't move.
Go to your local auto parts store and ask them to read the codes (most store provide this as a free service).

Go to Autozone,they will scan your Jeep for free,takes just a few minutes and they should be able to tell you why that check engine light is on.

its most likely a bad sensor. there are Many! have the dealer or autoparts store run a diagnostic.

Check your throtle postition sensor. It monitors what postion the throtle is at and sends that info to the ecm. It will go bad and cause that problem.

Sounds like an air leak somewhere after the air filter chamber.With engine idling spray some carb cleaner at different areas along the intake hose and the intake manifold,any place air can get in.If rpms change you have found leak.

I don't think the PCM is your problem, is the check engine light on? It could be you idle air control motor this is located on the throttle body, but because this happens while driving I am thinking you will need to replace your crank shaft position sensor it is located on the transmissinon bell housing it is very hard to replace without the correct tools. If the check engine light is on take it to a local auto parts store and ask if they can check the check engine codes for you they usally will do this for free.

Replace the throttle postioning sensor, and mass air flow sensor

Mine does the same thing when the oxygen senor goes out... About every 70k miles. doesn't always turn on check engine light

I had the same problem with my 99 Cherokee. I was told to replace the blower motor for the carburetor, works great and gas mileage improved.