95 jeep grand cherokee engine won't idle

Change the temperature sending unit/temp sensor. When starting, the sensor will tell the computer to put the engine in cold start mode to give a bit more fuel and raise the idle a little so it WILL start and keep running without ever touching the throttle. Once warm-up is completed, this sensor will tell the computer to stop the cold start mode and go to normal run mode. THAT is your only problem.

it is your air idle control valve witch is located on the back of the throttle body..

you just need to relearn the idle hold your foot on the gas about 10-15%and let it run for a few min then slowly release the gas

Because you disconnected the battery you lost the long trim value,you will now have to relearn the idle,start the vehicle idle it to 1500 RPM,hold for a minute,idle should stabilize,turn on A/C let it idle,for a minute,now your done,

The idle relearn needs reset. Keep your foot on the gas at about 900 rpm. Make it idle for about 5-6 minutes. Slowly ease up on the gas until it will idle on it's own, it might take a while. After you get it to idle, it might be idling real low, but on its own, Let it sit and idle until for 20 minutes. After that it should be back to normal. You will have to do this every time you have the battery unhooked for a while.

Have you pulled the code with a OBD II reader ? Please let me know which codes you find.

check intake manifold air temp sensor and engine coolant sensor...one may be out of range but not enough to turn on dash light. tests and specs can be found in chiltons or haynes, test is done with digital multi-meter.

i recommend cleaning the throttle plates. they are located unter the intake hose form the engine to the air filter housing. if you open them with the engine not runniong you will see they will be covered in carbon. use a good carb cleaner and a rag to wipe them clean

what generally happens with jeeps. is the idle air control valve loses memory of its idle position. try starting the vehicle with your foot slightly on the gas pedal. if it starts your going to have to keep it running by keeping your foot on the gas until it relearns its position and runs by itself. also there is a possibility that one of the modules locked up. if my first suggestion doesnt work then disconnect the negative batt cable for 30 seconds reconnect and then try to start it

A faulty gas cap can cause the sensor to come on.
Clean out the throttle body with a cleaner and see if the idle improves.