-Rudy-

Like the title states, I was driving the xj today and I noticed it had a small misfire while I was stopped at a light. I thought it was odd because it usually runs 100% smooth, so I revved it a bit to see if maybe it was just a rough spot of gas or something. I then took off from the light and noticed it was stumbling a little bit, so I gave it some more gas to see if I could get it back on it's toes.

It revved to about 3200 RPMs and then just fell right on it's face. I thought maybe it was the gear, but when I shifted to 3rd it didn't move. I tried all the gears and it was just slowly losing RPM and coming to a stop. As I neared about 10 mph, I tried putting it in 1st and popping the clutch, but to no avail.

When it stopped, I tried starting it and it would crank, but not turn over. About every 4 cranks or so it would sputter a bit and die.

Defeated, I called my dad and went with him to drop off some hay, then returned. Upon returning I cranked it once and it sputtered. I then cranked it again and it fired right up. I drove it to the ranch and back home without issues, but it still concerns me.

Any ideas?

I threw the scanner on it and it didn't throw any codes or lights.

F1Addict

Was it sort of a "Crap-I-just-ran-out-of-gas" feeling? Provided you didn't actually run out of gas, my vote is for either your fuel pump or CPS. Can you hear the fuel pump prime when you turn the key to the ON position? Doesn't rule out a bad fuel pump but it does help to know that it's getting power and spinning. I'd test your CPS next since failure of that fragile little thing exhibits the same symptoms.

-Rudy-

Yeah, it was exactly like that, but I had over half a tank.

It started and is now running just fine. So I'm not sure wth is up with it. The other day it started and was revving all over the place by itself, it felt like it had a big cam in it and when I took off it would lurch forward. You think that might be related to this?

F1Addict

Your second issue sounds more like a vacuum leak (which could also cause you to stall out) but those don't usually resolve themselves. The CPS doesn't always just fail, sometimes it fails a little then works again, then fails, then works. Perhaps your adventure the other day was just a friendly reminder that it's time to replace. They're not terribly expensive, around $50, I think. There are other sensors, the TPS (throttle position sensor) and the cam position sensor but I think they're less likely to be the culprit. Others can chime in if I'm mistaken.

-Rudy-

Hmm, I'll have to check those things out.

I thought it might be the coil since it fired up after I let it sit for about 20 minutes.

-Rudy-

Bump.

Drove it today, ran fine. Any ideas as to what caused this? Might just replace the sensors and coil for the hell of it.

F1Addict

I would recommend starting with the CPS. It's prone to failure and most of the symptoms you've described are consistent with it's eminent failure. While you're at the parts store, pick up 3 or 4 feet of vacuum line and systematically replace it as you have time.