hey guys i have a 1998 jeep cherokee 4.0l. About two years ago I started having major issues, it started with the hesitation while accelerating. Randomly the car would hesitat and slow down and if i stayed in the gas it would pop/backfire. next my belt start squealing on and off, one day on the highway the car starting hesitating then shut off. sent it to a shop and they changed my ignition, plugs wires cap and rotor and replaced my belt and idler pully. the car was fine for about a year. yesterday the hesitating came back i looked at the belt today and it seems to be eating itself up. i replaced plugs, cap and rotor and seems to have gotten worse..any help would be greatly appreciated thank you!

 

also forgot to add, the car wouldnt idle like normal. if i left it running it would start acting rough and smelled like fuel.

 

I'd check and clean/adjust the TPS and IAC valve. IAC for rough idle, and TPS for hesitating at driving speed.

 

one thing id check is take the belt off and turn each pully by hand and see if any of them are siezed up.....had a buddy with a chevy truck and the belt was squealing and eating itself, turns out the alternator was halfway siezed up and the belt was riding on the pully.

 

Stop replacing your plugs, cap and rotor. Your tune-up should be ok for several thousand km's (or miles ) and if you checked to see the first replacement has been done ok, leave them for now.
Besides the belt issue (which I can't advise on) , I think you should look at your CPS (crankshaft position sensor). What you describe, starting two years ago, with your stalling whilst driving/backfiring/popping: typical symptoms of a CPS going bad.
You have a 4.0 ltr engine, and the CPS on this will eventually fail. If its not been done, have it replaced (pref one from dealer). Good chance you fix your stalling (and likely some starting) issues if present and go from there.

 

^ I agree with the possibility of a failed CPS.

And you did not need to do another tune up, as your problem more than likely lies somewhere else. What plugs did you put in? And we're they gapped correctly? Did you verify that you got the firing order correct?

Also verify fuel pressure at the fuel rail. Always a possibility of a fuel delivery issue

 

Thanks for all your input, I forgot to add I changed the cps when my problems first starting occurring. I removed the IAC valve and it was very dirty, so I cleaned it up. No more hesitating but the car still doesn't feel the same. I'm going to check out the tps today. Thanks everyone for the help!
I used champions, my old plugs were very beat up for only 15k miles