88 4.0 automatic looses power with backfiring

[Autocrossk20]

I have an 88 cherokee happened out of no where last year when the truck is under load it feels like it looses a cylinder the rpms drops 1k maybe more it back fires sounds like it's right underneath me by the down pipe if I put the gas to the floor it hesitates downshifts and rips but anywhere before that it's dogsh** someone please help!!!!

 

[superj]

have you checked your sensors? you should have the older fuel injection system which is very easy to trouble shoot with just a multimeter.