This problem has been intermittent for a while, but as of friday it has been more and more a problem! I have replaced my TPS being that I almost have no throttle when this happens. My 96 XJ 4.0 will buck and act like it's trying to backfire, I can watch the tach needle go up and down a couple hundred RPMs and the speedo stay where it was then start dropping cause i have no throttle. It'll do it in any gear at any speed, yes even neutral. I'm honestly stumped on this one; I've checked for a vacuum leak, my fuel pressure is good, and my transmission is full. I have noticed that I'll smell rich and almost like a two stroke but no smoke comes out the back end. This problem only occurs when I'm driving, NEVER at idle. Anyone have this problem before?

Thanks in advance,
Redwolf

 

O2 sensor maybe?

 

thats what i thought but it's not throwing any codes for an O2 sensor or bad cat,

redwolf

 

96 was a year of change for the fuel delivery system on the XJ.

Do you have the fuel pressure regulator under the hood or is yours the later 96 model with the entire assembly in the gas tank?

Reason I am asking is that the fuel pressure requirements are vastly different. 31 psi for the old style, 49 psi for the new style.