I have a 01 grand cherokee with a 4.0. Just this week, with temps in the 20s, it did not start with just a turn of the key. It took several seconds of cranking and pumping the gas pedal to start. Once started I released the pedal and the jeep died... there was nothing. I started it again and this time kept the accelerator pressed down to keep the rpms above a grand. The vehicle will stay running at that point. If i release the accelerator it dies again. Only keeping the rpms above 1k will keep it running. When the engine warms up things start to improve. As it gets warmer it will start to idle in its own for a few min, but rough, and then finally when the engine is warm the engine will start right up with no resistance and the idle will be smooth and the jeep will drive fine. It is now in the 40s and am still having the same problem with the jeep, so its not extreme cold only, just cold. I have read lots of post and it seems like there are 50 things this could be. I'm guessing IAC and coolant temp sensor may be the culprits but don't want to dump tons of money into it if it is maybe something else. I know I am going to have to probable replace a few things before the problem is pinpointed, but just would like to know the best sequence to do try repairs. Thank you for any help. I can provide any more information about this problem that is needed to help get this fixed. There are no indicator lights or codes.