One problem related to ignition module has been reported for the 1997 Jeep Grand Cherokee. The most recently reported issues are listed below.
Driving up a very steep hill at night. Car starts to buck wildly, loose power, rpm goes constantly from 300 to 2000. Seems fuel starved. Over hill, engine seems to run fine. Then on highway at 70 mph, engine shuts itself off, twice within half hour. Dealer says computer chip and replaces, but not fixed. Then says fuel pump. Replaces. Now six weeks later, same thing happening to car. Not fuel gauge problem, as tank 3/4 full.