i have an 89 xj. it will sputter and idle really low for a min then kick back up, it would do it when i was driving and let off the gas to come up to a stop sign or turn(at least thats how it started). it has got progressively worse now it does it when i put a load on the engine (climbing a rock, power brake, ect.) and is to the point that it will just die. it starts back up just fine and run like a champ at wide open throttle. i first thought it was the O2 sensor but i replaced it with no change in the problem, then after reading some other forums it started to sound like a throttle position senor so i replaced that. once again no change but then i got curios and decided to unplug the tps and try it and it seams to have solved the problem ( no sputter, no die, sounds good). WTF? any one have this issue.

 

So when u have the tps disconnected it runs fine? Not a Renix expert but I recall the TPS needing to be adjusted in those years. That could be one cause. Your tps being crap right out of the box a second cause. Find Cruiser54's Renix tips.

 

Ok thanks how do I test the tps this one has two plugs a three prong and a four prong? How do i adjust it once its in?

 

Like I said, find Cruiser54 Renix tips.
Look for a post from him and go to the pink link below in his signature. With your Renix, you will find a wealth of info and things-to-do.

 

^^This is where you want to start^^