I was driving my 96 JGC last night, when my rpm indicator went to zero for about 2 seconds, and it felt like I lost all power but the lights, radio, steering, etc were working, and then it seemed to run fine after that. What was/could be the problem?

Check the fuses and the battery is trying to die

Look to replace the TCM throttle control module

maybe timing chain or belt jumped or broke

what makes you thing the tires/wheels tighten (felt by hand off ground?)
my guess , you meant it seems. like???
1: lost engine power?
2: transmission not up shifting?

is this a auto A/T or manual M/T tranny,
if A/T , you need to look at the engine RPM when you lose
power (acceleration on demand)

RPM rises, car dont move faster ,this is tranny slip.
RPM fails to increase, and speed, up hills. this is called lost engine power.
lost engine power can be caused by , bad spark (tuneups skipped?)
or weak fueling.
weak fueling too can be cause by skipping the fuel filter step in the tune up list.

Sorry to say this , but its the ECM computer. Altenator runs threw this and it is dieing or dead.You can get one at a junk yard . you will have to pull yours first. there are numbers on them that have to be matched up. junk yard should be able to help you on this. It will still need flashed/reprogrammed. Some auto stores can do this at a fraction of the cost of the dealer. call around.

Ether way it sound like the battery is low on power. If it is a new battery then it may be the alternator.

Check to see if the belt [ s] are still on the motor. You may have had something seize and break the belt that powers these items. There is also a seperate belt that powers the A/C [ lower right side of engine ].

sounds like the alternator is going out sometimes it works sometimes it doesnt it will blow the battery up if not taken care of

A blown fuse inside the power distribution box. It could be a fluke, youll know if it blows right away.

try a cam sensor as this monitors timing,could be getting weak and loseing it then repicking up