have a 1993 jeep grand cherokee with a v8 all wheel drive. It started sputtering, and than it started to die when i was stopping. The battery gage spikes up when it starts to sputter really bad, but it doesnt go into the red area, also the oil pressure spikes up too. If it sputters for awhile it gets a really strong gas smell. We tried changing the fuel pump a few days ago, along with the air filter. We also used fuel injector cleaning hoping that would help the problem. The check engine light has never come on, but the computer says to service the four wheel drive switch. Should we try to change the spark plugs and wires... or does it sound like a bigger problem?