Engine Stuttering

[Tim Redman]

My 2005 Wrangler is doing what I can only describe as a very subtle stutter. I'll try to be more descriptive.

When I'm at any kind of cruising speed, I can feel the engine very very slightly running unevenly. It almost feels like a transient misfire, but it's not enough to trip any kind of engine code.

Since I have an 05, there's no Schraeder valve on the fuel rail, so I can't check fuel pressure until I get an older Wrangler or Cherokee rail to replace it. I dropped the tank this past weekend to replace the fuel pump, since I happen to have a new one sitting in the box, but I was unable to get the retaining ring off, either with the tool or banging it with a screwdriver. It's wedged on pretty tight.

I've cleaned just about every component on the intake to no effect. If I downshift, other than a brief, split second hesitation, it seems to still have plenty of power. I've done a cursory check of the vacuum system, and so far, all I can find is a slight leak at the throttle bushing, but from what I understand, that's common with most Jeeps, particular this age.

I do have a new coil pack being delivered tomorrow, so I'm going to throw that on, but is there anything else anybody can think of that I should look at? I can provide any more information that I can on request.

Tim

 

[Jerry Bransford]

Use a big strap wrench to remove and then tighten the nylon lock ring when replacing it. I only found one big enough in the plumbers section of Home Depot, the ones in their tool department were too small.

For the misfires I'd probably first suspect the crankshaft position sensor. If you are it go with a good brand like Standard Motor Products if you can't find a Mopar. Avoid store brands for critical parts and sensors.

Good luck with it!

 

[Geepum]

I know I’m new to the forum, but I’ve been a drive-ability tech for many years. I just want to throw out that I’ve seen many a shuttering converter clutch feel just like what we call a tip in misfire. You only feel it with slight acceleration at cruising speed and no codes usually set till it gets real bad. I’ve even seen it set misfire codes. Don’t know if it’s common on your trans. Just food for thought. Also a down and dirty fuel pump check is a wide open throttle pull. If your engine can maintain good power all the way up to redline without feeling like it’s starving for fuel, you can almost rule out the pump causing idle issues. The pump is under the most strain at high load/high rpm. I won’t say always or never. There’s usually an exception somewhere

 

[L J]

Use a big strap wrench to remove and then tighten the nylon lock ring when replacing it. I only found one big enough in the plumbers section of Home Depot, the ones in their tool department were too small.

05-06 has a stamped metal lock ring

that uses a tool like this

 

[Jerry Bransford]

05-06 has a stamped metal lock ring
View attachment 472469
that uses a tool like this
View attachment 472468

Damn, another reason I'd never buy an 05-06 TJ.

 

[Geepum]

You can get them spun on and off with a hammer and brass drift, but yeah, I’d rather have the tool. Thants just like the retainer US manufacturers have used back in the old days, but larger diameter

 

[Tim Redman]

Well, the new coil pack is in, and it really doesn't ride any better or worse than it did. Positive out of that is that I have a new coil pack and a 160k mile functioning spare to stick in the spare parts cabinet.

I ordered a Mopar CPS that should be in by the middle of next week, so I'll wrestle with that when I get it and see if it helps at all.

At some point, I'll muster the enthusiasm to drop the fuel tank and give the fuel pump another go. But in the true spirit of troubleshooting, I'm just trying one thing at a time for now, instead of a dozen things and wondering which one actually worked.

 

[Jerry Bransford]

I know I’m new to the forum, but I’ve been a drive-ability tech for many years. I just want to throw out that I’ve seen many a shuttering converter clutch feel just like what we call a tip in misfire. You only feel it with slight acceleration at cruising speed and no codes usually set till it gets real bad. I’ve even seen it set misfire codes. Don’t know if it’s common on your trans.

Are you talking about the lockup clutch for the torque converter? If so I haven't heard of that problem in a TJ but I guess it's a possibility.

 

[Geepum]

Are you talking about the lockup clutch for the torque converter? If so I haven't heard of that problem in a TJ but I guess it's a possibility.

Yes sir. Yeah, I wasn’t sure if a clutch shutter was common in his trans. Over the years, I’ve seen it in various makes and models. Just wanted to throw it out there cause it’s bit me in the ass once and others too.

 

[Jerry Bransford]

Yes sir. Yeah, I wasn’t sure if a clutch shutter was common in his trans. Over the years, I’ve seen it in various makes and models. Just wanted to throw it out there cause it’s bit me in the ass once and others too.

Ok yeah that makes sense. I'm guessing it's not a problem in TJ automatics, I've been closely following TJs since 1996 in many forums and have never seen it mentioned.

 

[Geepum]

Ok yeah that makes sense. I'm guessing it's not a problem in TJ automatics, I've been closely following TJs since 1996 in many forums and have never seen it mentioned.

That’s good to hear. I’ll store that tidbit away for future use.

 

[Geepum]

Well, the new coil pack is in, and it really doesn't ride any better or worse than it did. Positive out of that is that I have a new coil pack and a 160k mile functioning spare to stick in the spare parts cabinet.

I ordered a Mopar CPS that should be in by the middle of next week, so I'll wrestle with that when I get it and see if it helps at all.

At some point, I'll muster the enthusiasm to drop the fuel tank and give the fuel pump another go. But in the true spirit of troubleshooting, I'm just trying one thing at a time for now, instead of a dozen things and wondering which one actually worked.

Good call on your strategy. Please let us know your outcome. If you were in my area, you’d be welcome to come by my shop where we could throw some diag equipment at it.

 

[Tim Redman]

Well, the crankshaft position sensor came in. However, the service manual indicates that there should be a paper spacer on it. Even though this is a new MOPAR part, there was no spacer on the sensor. When I emailed the dealer about it, they said that the part mentioned in the service manual actually belongs to a YJ. Is this some kind of generic spacer that I can source from a local auto parts store, or is it something specific to this particular part?

The Wrangler is a 2005 4.0 I6 with 6-speed NSG370 transmission. The sensor is a 4727451AA, the manual states that the spacer is part number 05252229, but the only one I've been able to find lately is a 05252229AA, which the Chrysler site says superceds the original. However, the customer support person there says it's for a much older vehicle.

I don't want to throw a part in the car that's going to eat itself by being improperly installed, and I'd appreciate any input that anybody has.

 

[Tim Redman]

One thing I have noticed is that, any place I look online, from the cheap sensors to the expensive, none of them show a spacer in the photo, nor indicate that one comes with the unit. I also haven't seen any mention of the spacer in any YouTube videos regarding installing into a 2005 with a manual transmission.

 

[Tim Redman]

The more I think about it, I don't think the CKP for the 4.0L 6-speed needs a spacer, and it wouldn't do any good if it were there, since there's no real way to adjust the depth of the sensor. I have a commitment tomorrow afternoon, so I'll wait until after that to give it a shot, in case I bugger something up.

If that doesn't fix my problem, the next step is to hit the u-pull-it for an older Cherokee/Wrangler fuel rail that I can plug a pressure gauge onto.

 

[JKP]

There's no spacer on the 6 spd version.

 

[tr21triton]

New replacement sensors will be equipped with a paper spacer glued to bottom of sensor. If installing(returning) a used sensor to vehicle, a new paper spacer must be installed to bottom of sensor. This spacer will be ground off the first time engine is started. If spacer is not used, sensor will be broken the first time engine is started


that seems crazy to me, just how does a piece of paper stop it from breaking only the 1st time it starts and why doesn't it break after the paper is gone ? just went and checked my spare and it has no paper either !

 

[JKP]

Also check the wiring harness that goes over the dipstick for wear.

Once you check everything else out, you may have a failing PCM. Known issue on 05 and 06. IIRC, tapping around the PCM connectors may reveal intermittent connections.

 

[JKP]

New replacement sensors will be equipped with a paper spacer glued to bottom of sensor. If installing(returning) a used sensor to vehicle, a new paper spacer must be installed to bottom of sensor. This spacer will be ground off the first time engine is started. If spacer is not used, sensor will be broken the first time engine is started


that seems crazy to me, just how does a piece of paper stop it from breaking only the 1st time it starts and why doesn't it break after the paper is gone ? just went and checked my spare and it has no paper either !

The paper spaces it away from the flex plate while you tighten down the screws. It sets the gap. Only applies to ATs.

 

[tr21triton]

The paper spaces it away from the flex plate while you tighten down the screws. It sets the gap. Only applies to ATs.

that isn't what it says in the manual, the way I read it.
Sensor With One-Bolt Mounting (NotEquipped With 42 RLE Automatic Transmission):New replacement sensors will be equipped with apaper spacer glued to bottom of sensor. If installing(returning) a used sensor to vehicle, a new paperspacer must be installed to bottom of sensor. Thisspacer will be ground off the first time engine isstarted. If spacer is not used, sensor will be brokenthe first time engine is started.(9) New Sensors: Be sure paper spacer is installedto bottom of sensor. If not, obtain spacerPN05252229.(10) Used Sensors: Clean bottom of sensor andinstall spacer PN05252229.(11) Install sensor into transmission bellhousing