Okay something started happening to the jeep today that ive never experienced.

4.0 99 134k miles

As I'm driving down the road about 50-65 the thing will lurch a bit, the rpms hit zero...for a split second its as if the engine dies and if I let off the gas it spins right back up and is going fine again.

Its done it now again this evening and the check engine light pops up for the same split second as the problem.

There's no way this isn't something relatively serious so I'm pretty freaked out.

 

Imma call it a fuel pressure issue at this point

 

My wife's 94 sport did that on and off until she would not drive it. I finally fooled/checked stuff til it would not start,, BUT IT THREW A CODE..It came up with cps and or cam sensor.Changed both,cps a real pain to change,now running like new with 210k on the clock.If you can check for codes might be first signs of same thing.. HTH Wayne..I had a lot of help from this forum..

 

Intermittent issue for "a split second" is likely electrical, rather than purely mechanical.

Simple stuff first:
Have it checked for stored codes
Check battery connections and grounds, make sure they are ALL clean, shiny and snug
Spend some time in the engine bay (and under the dash) to check for loose/corroded connection

THere can be several things causing this, from simple loose connections, to faulty sensors, relays etc etc.

Given the split second character of the symptoms, you likely not catch it while it's doing it, which makes this a bit of a challenge. But start with the above, I'd say. Diagnostic procedures for other components can follow later.

 

I've checked in the last couple months and the only one to speak of is a shorted downstream 02 sensor.
Something may obviously have changed in that period of time but I will also add that she doesn't seem as spry as she did 2-3 months ago. The pedal feels less responsive, some lag in the overall power band but then nothing real noticeable while cruising. I'll get the solus on her and see what's up. I've recently done the big 3 minus the new alternator have yet to get the new 160 in there, there may be some disconnections somewhere.
Thanks for the quick responses men!

 

You assume I'm a male. That is jumping to conclusions.
If you keep calling your car a she, I'll have to leave you to someone else, see my sig. lol.

 

I just hope the OP doesn't dump her just because she is not as spry as she was 2-3 months ago!

 

I also ran into a similar situation where mine would momentarily cut off in a right turn , then cut back on as I straightened the wheel. Turned out to be the wiring loom in my 97 between the fuel rail& fire wall. .. it had been rubbing on the rail and had warn through the loom, so under the right circumstances, exposed wire would contact the fuel rail& short to ground. After a few days of reading the interwebs, I ran across something that said this was a known issue. Anyway, if there is no code (or even if there is) , it might be worth checking. A little insulation repair and a zip tie or two fixed min in about 10 minutes.

 

My jeep is more valuable to me than either of your lives.


And thanks Juan I'll do some trouble shooting!

 

My bets on it being the Crank shaft position sensor.My 99 did the same thing about 2 years ago.I changed out the Crank shaft position sensor and its been fine ever since.

 

Now it won't start...plenty of turn over just seems like its not getting gas I'll try the sensor though

Yeah after thinking and researchin imma say its that sensor

 

We gotta admit that a carb and a points type distributor were easier to fix...

 

Yep. A loss of fuel pressure that sudden? Ain't happening.


The CPS is famous for failing intermittently.