Engine Stuttering

[tr21triton]

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.

do you have 1 bolt or 2 bolts holding the sensor in ?

 

[JKP]

It has one bolt, and as he stated, the spacer wouldn't do anything the way it mounts as there's no adjustment. There's no spacer on an 05 or 06 MT crank sensor. I have replaced mine with a MOPAR before and have the old one in the glove box as a spare.

 

[Tim Redman]

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.

Very much a last resort, as I'm sure you know how hard it is to replace the PCM on those years. I haven't ruled it out, but I'm checking the easier and cheaper alternatives first. If nothing else, the old girl is getting fresh new parts.

 

[Tim Redman]

It has one bolt, and as he stated, the spacer wouldn't do anything the way it mounts as there's no adjustment. There's no spacer on an 05 or 06 MT crank sensor. I have replaced mine with a MOPAR before and have the old one in the glove box as a spare.
View attachment 474324

Definitely a good method to follow. Anything I take off the Jeep, even if its performance is substandard, as long as it still works, it goes in the spare parts cabinet. Always a good stopgap until a new replacement unit arrives.

 

[JKP]

Very much a last resort, as I'm sure you know how hard it is to replace the PCM on those years. I haven't ruled it out, but I'm checking the easier and cheaper alternatives first. If nothing else, the old girl is getting fresh new parts.

Well, it's not hard. Just expensive.

 

[Tim Redman]

Once again, @Jerry Bransford gets a cookie. Put the new CKP in and the car run considerably smoother, and there's no hesitation from a full stop. It doesn't run like a new car; I mean, it's still a 160,000 mile solid axle vehicle old enough to vote, but I no longer feel the stuttering or the sudden slight lurch at cruising speeds. I was only able to test it at 45mph, but I'll give it a higher speed test tomorrow, as I don't live far from an interstate. However, looks like my trip to the junkyard and my struggles with removing the fuel pump have lost a couple of notches of urgency for now. At least until the next thing pops up.

Thanks to every who had valuable input here.

 

[Tim Redman]

Well, it's not hard. Just expensive.

Not hard as in the process, just hard being without a vehicle while I wait for a PCM swap.

 

[tr21triton]

Once again, @Jerry Bransford gets a cookie. Put the new CKP in and the car run considerably smoother, and there's no hesitation from a full stop. It doesn't run like a new car; I mean, it's still a 160,000 mile solid axle vehicle old enough to vote, but I no longer feel the stuttering or the sudden slight lurch at cruising speeds. I was only able to test it at 45mph, but I'll give it a higher speed test tomorrow, as I don't live far from an interstate. However, looks like my trip to the junkyard and my struggles with removing the fuel pump have lost a couple of notches of urgency for now. At least until the next thing pops up.

Thanks to every who had valuable input here.

Jerry is a walking maintenance manual and parts catalog for TJ's !

 

[Tim Redman]

Jerry is a walking maintenance manual and parts catalog for TJ's !

I've come to trust him on things Jeep. If he's ever wrong, he'll be the first to admit it. But that doesn't happen often.

 

[Tim Redman]

I guess my next question is whether or not there's any way to properly test the old one. Before I removed it, it was still functioning, though obviously not 100%. After I inspected it, it was covered in gunk, but all of that wiped away and the thing is now as clean as it was when it was new. Could the debris that was on the business end affect the readings, or are there internal components that just go bad, and that's the way it is? Is there a way to put power to it and test it? In any event, I'm still going to keep it as a (somewhat) functional spare just in case.

 

[Tim Redman]

As an extra note, for anybody who's never replaced the CKP on a later model 4.0 TJ with a manual transmission, it's absurdly easy. There are just two things I ran into that might be of note:

1. Removing the single bolt is quite easy with a 1/4" drive wrench and deep well 10mm socket. Putting it back in can be a little tricky and frustrating. My advice is to not try and use your fingers alone to get the bolt started. There's just not a good angle for it if you're coming up from underneath. Take the socket off the wrench and put it on the bolt. It will give you and extension of sorts and something to manipulate that isn't so tangled up with the body of the CKP. Once you get it started, and you're positive you haven't cross threaded anything (under normal circumstances, it should screw in quite easily, almost right down to the sensor mounting bushing), then you can put the wrench on the socket and tighten it up.
2. Some people have reported that, with a decent body lift, you can reach the sensor from the side. For the rest of us who have to come up from the bottom, be aware that just a few inches to the side of where the sensor mounts is your A/C condensate drain. Wear safety glasses, especially if the Jeep has only been sitting long enough for the exhaust to cool down.