engine backfiring

hey to all, new to the forum been on ju for a while now
i have a 1990 mj, 4.0 aw4

well i got a little to big for my britches, tried crossing a 4ft deep pond and along the way, water ran up my exhaust and killed my engine
i got it home and the only problem i have now is engine backfiring

i pulled my plugs and they're pretty gummed up and smell like gas, i am thinking the water tore up my coil, either that or my injectors arent firing right

do you guys think water in the fuel tank is possible? i already added a can of dry gas

bump

I'd run a compression check. You may have warped a valve. Are you sure you didn't take on water through the intake?

Most everytime, I´ve gotten in deep, I´ve found water in distributor. Often some moisture in plug cable boots (if they are old and hard). And some moisture in assorted connectors.
Look in the air box, for a wet (or collapsed filter). Always check out the inside of your alternator, as best you can with a flashlight. If there is mud or sand in there, it can mess up your brushed quick.
A vacumn gauge will tell you quick if you have valve trouble, needle jumps all over the place. But I´d have a look at the ignition system first, all the high voltage (plug/coil) wire boots.
Compressed air works best, spray cans of whatever are often a waste of time. WD-40 is to be avoided, especially on sensor circuit connectors.

It would be rare for the water to go up your exhaust. I would check your intake and ignition for signs of water.

i'm pretty sure the main cause of the problem is water in the fuel, i'm going to drain it and put fresh gas in it, also i think i may not be gettitng a good spark

do you guys think i would of actually been able to drive my truck for 45 min all the way home with a bent rod?