99bluexj

My 99 XJ has just under 100k on it. In the last couple weeks I have been experiencing occasional engine "stutters," or at least that is what it feels like. It only seems to happen when I am casually on the pedal cruising at a consistent speed (and even then, it is seldom, but it has been happening more frequently lately). It has happened on both level roads and inclines but never while going down hill. It has happened on backroads while cruising around 45-50mph and on the highway in the 60-70mph range. When it happens, it feels like the engine just missed a beat for a split second, kinda like the feeling of hitting a quick small bump. It runs fine otherwise although my wife recently had trouble starting it (it took her 3 tries to get it started at a convenience store last week but I drive it daily and have never had a problem starting it) and it kind of feels a bit low on power lately. Other than that, I have the P0455 code which I have had for a long time but don't know if that is related. My gut is leaning towards a fuel system issue but I'm not sure. Any insight or suggestions would be greatly appreciated. Thanks in advance!!

Lije

I REALLY hope someone has an answer.

Mine has been doing this for a while now and I have NO clue what it is and I haven't had the money to put it in the shop.

I wanted to post something on here to see if anyone could help but I couldn't describe it (really good job btw).

Anyways, hope someone has a simple, cheap fix for the problem.

Jeroen

The symptons you describe are likely to be something with the ignition and or fuel systems.

Not sure what your code means. Sure somebody will chime in.

But for starters: I've had these sort of problems on a number of my cars. In a couple of cases it turned out to be the spark plug leads. These are all High Voltage any bad connection or poor insulation will almost certainly give performance issues

Make sure that all the connections are clean on both ends. So pull the leads of the plugs and the distributor cap and the coil. Inspect them visually and replace if you see any cracks.

Same for the distributor cap and rotor. Take them apart and inspect and clean thoroughly. Any cracks and they should be replaced. Check for any major burning on the inside of the cap.

Jeroen

tjwalker

I agree that making sure all tuneup hardware is fresh is a good idea. That includes plugs, plug wires, distributor cap, rotor. Don't want to be chasing your tail for $40 worth of tuneup parts.

When it skips, do you see the rpm needle drop and then come back almost instantly? If you do, that is a clue that you are losing ignition.

The P0455 is a gross evap. system leak and is not likely related to your symptom, but you should resolve it anyways. Suspects include a leaky/faulty gas cap or a leak anywhere in your evap system from the gas tank to the charcoal canister. But start with the gas cap. Buy a quality aftermarket cap or get one from Jeep to help rule this out before digging into the evap system.

ezab

Do your RPMs drop down and go back up more than one time when it "stutters"?

Lije

I don't have a tachometer in mine so I'm not sure.

99bluexj

No, I have not noticed the RPMs changing at all when the stutter occurs. If the RPMs don't change, that would rule out ignition, right? If so, then would you look toward the fuel filter and/or pump next?

(Regarding the P0455 code, I'm already working on that one but still haven't been able to diagnose the issue. I've changed the gas cap, inspected the evap hoses, and even changed out the two that run along the fuel rail back to the canister where I suspected the leak may have been. But so far the code keeps coming back. I'll figure that one out eventually but am glad to hear that it isn't related to the engine stutter which is a bigger concern at the moment.)

Thanks again for everyone's feedback! It is really appreciated!

Cherryokee

A defective Evap Purge Solenoid can cause the described conditions (with P0455, but no leaks were found). Borrow/swap it with a Jeeping friend just to prove it out - compare observations between them after a day or two. That's how I determined that I had a bad one before grabbing a replacement at the JY.

99bluexj

Cherryokee, just to be clear you are saying that a defective Evap Purge Solenoid can cause the engine "stutter" problem?

Cherryokee

Speaking from past experience, yes, and replacing it eliminated the "stutter" as well as an incessant ticking sound. This is obviously not an absolute solution - take this advice with a grain of salt - it was a low $$ approach and it worked for me. You may have other variables at play and it seems that you're on the right track.

tannerp89

this might be a far stretch...but clutch issue maybe?
getting higher in miles, "stutters" in higher gears at cruise and under load, but not down hills is what sets this off for me.
could be starting to slip in the higher gears when your tranny starts to gain mechanical advantage, less load on drivetrain going downhill which means no slip...plus general loss of power...could be time for a new clutch

ezab

Thats exactly what I was thinking. Possibly a torque convertor thats going bad. Mine was doing the same thing, switched the TPS and changed the trans fluid and filter, it hasn't happened since but I am not getting my hopes up that something that simple fixed it.

99bluexj

I just went out, popped the hood, and fired up my Cherokee. After a few minutes the evap purge solenoid started ticking. When I touched it I could feel it tapping along with the ticking sound. Are you saying that sound is indicative of a failing solenoid? (I realize this may or may not be the source of my engine stutter but if the solenoid is failing then I would definitely want to replace that first as a good place to start.) Please let me know.

Thanks again to everyone for your feedback.

tannerp89

that means the solenoid is good, mine does that also.

95XJsport

mine just went through that problem. i had a combination of 2 things the first being a faulty cam position sensor, and the second being a bad distributor bearing. caused too much play in the shaft and made it wiggle back and forth, once i replaced the shaft starts and continues running just fine now