EHarris

Man I'm sorry to hear. I think next step is to catch it on video for a post to see how bad this really is. That was everything that I did and the coil pack solved it for me. Wish I could be of better help. But for good maintenance measure I did plugs, wires, coil pack, PCV valve, starter, alternator, Battery. They all were starting to get pretty tired after 150k.

KClight01

Well, I have more time to work on this recently. The jeep is around 80K miles. I was sure hoping the ignition coil would solve the issue. I still think it is the CAM sensor, even though I replaced it 3 times and still no code. The reason is that the symptoms match the service bulletin where the jeep starts fine, after turning key off, on second try after long crank. I may try the wire connector next, the wire loom was disintegrated before I replaced it, but the wire looked ok. Maybe the jeep just wants more quality time with me, even just sitting in the driveway.

KClight01

Update, wow dealing with this for a while now. I just replaced fuel pump and it started and runs great. After a few a few starts, it finally did the extended crank crank crank again. After more research I am now thinking it is related to the TIPM fuel pump relay that is causing this issue, not the other sensors because the jeep runs great otherwise, and fuel pressure and trims are perfect after replacing the fuel pump.

KClight01

I verified it's not the TIPM fuel pump relay. New fuel pump and pressures still good. I reseated the cam sensor this morning, previously ordered some spacers so I used one. It had some oil on it so I cleaned and reinstalled. At least for my sensor there seems to only be one position when you seat it all the way down, it stops at the groove for the bolt. I really don't understand how it runs great (~18 mpg) with no codes but still gets this extended crank and stumbling start after warm and sitting for a while, but then cranks right up when you turn the key of and then start again. I feel like I am the last one with a still driving an older JK and still dealing with this.

Mr.T

Have you checked for DTC's with an enhanced scanner?

https://www.jk-forum.com/forums/jk-w...er-pan-353031/
Your description of installing the cam sensor sounds like it could be the problem, the sensor should be able to hit the rotating surface on the timing gear when pushing it down without that paper spacer. See the latter half of the write-up in the link above. The cam sensor may be damaged or improperly manufactured, the bolt slot should not bottom out before the sensor hits the rotating part, especially with a spacer installed on the tip of the sensor. Essentially it means too much gap. If you have to, file away plastic in the slot so it can go deeper. If the sensor isn't mis-manufactured or damaged, it's probably from the tolerances stacking up, including the slop in the position of the timing cover relative to the engine block.

Mr.T

After re-reading your post, I think the problem is that your cam sensor is not going deep enough. I added more to my previous post, just wanted to make sure you saw it.

KClight01

Hey thanks for trying to help me figure this out. I saw your post previously and was actually thinking of trying to "raise" it slightly. Now I am wondering if it is not going deep enough, crazy. I plan to look closely again today at all the wiring, grounds, and perhaps try to reseat again. I used to think the paper spacer was critical, but now I am starting to think that it probably can be adjusted by trial and error. I probably have 3 or 4 of the spacers in there now because they probably don't really disintegrate, not sure if that's a good thing or not. All I know is that I push in as far as it can go, it seems to "bottom out" and you really can't go any more, and if it did, you would not be able to put the bolt in. I might try to "file" one of the old sensors and see if I can get it to go deeper and still install. Or I might try to back off first and see if it makes a difference. One problem with this is that it hard to know immediately, I never get code and jeep runs good otherwise (I have a good OB2 scanner, it should read all codes). It might start fine for instance and run fine for a few starts, as I do whatever "test" then I have to drive normal and let sit for ~45 mins, and try to start to see if it made a difference or not. Temperature, timing, and pause time before crank all seem to make a difference, and probably many more variables and things to check, or maybe it really is the CAM, maybe it has some kind of internal short that occurs under certain conditions. If I test the ground and voltages when running it may read fine, but it may change after sitting, I'd have to test and document all these conditions. Again, I have a new fuel pump, pressures are good, injectors don't seem to leak, fuel trims are good, vacuum pressure is great, no leaks, 1 year old battery reads good, new alternator ~1 yr old, reads good. It's got to be electrical or related to the CAM sensor, I also replaced the crank sensor a couple years ago, and I think the old was probably fine. It would be great if I could verify this long issue has been to the cam sensors not being pushed in far enough...

Mr.T

What I can say for sure is that the tip if the sensor should be about .030 from the rotating part, which is the thickness of the disolvable spacer.

When it bottoms out, the tip of the sensor and the rotating reluctor are touching. With the spacer method, it should bottom out at the correct gap and the bolt should go in without pulling the sensor outward. If not, do whatever it takes to get it that way.

The other (non-spacer) method, is withdrawing the sensor .030". It's what I've done a few times and it works well. But it depends on a good eye for measurement. Might as well use the spacers if you have them.

Obviously there should not be any rub marks (from contact) on the sensor or the rotating part. On a side note, I have seen a mis-manufactured crank position sensor that was barely rubbing the reluctor on the flywheel. No adjustment on the crank sensor like the cam sensor has, it's just toss it and install another one. Bottom line is that tolerances stack up, and manufacturing tolerances aren't always adhered to. Just have to figure out how to work arounnd the issue sometimes.

KClight01

So going full circle on this. Do you think my issue could be due to bad crankshaft position sensor? I've watched some videos and most seem to replace both (the cam and crank) sensor at the same time. I went ahead and bought an autostore OE brand cam sensor this morning and checked the resistance and then compared it to my current cam sensor. It seemed to indicate my cam sensor is failing (low resistance then reads OL on multimeter), the new sensor read a constant resistance. I replaced the sensor and everything seems good, still running good no codes, then I waited the ~1hr after hot engine, and sure enough I got the long extended crank again, more than 5 secs so I turned key off, then on again and started right up, just like before. I am thinking of replacing the crank sensor next or compare it to a new one. I don't think I've seen any posts saying a long crank solved due to crank sensor, most get a code to replace it.

For the cam sensor, I did not play with the position like I was thinking of doing, I used the spacer and seated it like before. The more I think about it, its position is correct or at least within tolerance, otherwise it would throw a code.

Mr.T

Yes, I think the crank sensor can cause that symptom. Very easy to replace, takes 5 minutes. The "fail when hot" is a classic symptom for any bad sensor.

I would not rely on tests with a multimeter, it's a solid state device and different brands of good sensors may give various readings.