Dirty_XJ

I did a search on this and couldn't find anything, but I'm also new to forums so sorry if It's been answered before. Anyways, I have an 88 4.0 auto and sometimes it cranks for 5+ seconds before starting then idles rough but will smooth out, and will drive fine... Until you let off the go pedal, then it dies. Every time.. I found a couple vacuum leaks that seemed to help her idle a bit smoother but I still not the best. I also changed the plugs and wires (ngk v-power, and accel 8.8 wires) any input is greatly appreciated as this is my first Jeep so I'm not familiar with common problems.

RTorrez1

It sounds like that you may have a fuel delivery problem. I would start by checking the fuel pressure at the fuel rail with a mechanical pressure gauge. If I'm not mistaken for your year the pressure should be around 39psi.

gpeade

Not sure since the year difference (mine is a 98) but my throttle position sensor was acting up giving me the same issue.

Dirty_XJ

Thanks guys, I will see if I can borrow one of my dad's gauges to check rail pressure and how much would a tps set me back?