Hi everyone,
It's been almost a year without any issues on the 1996 Jeep Grand Cherokee Laredo, I'm up to 177K miles and starting to have a couple of new symptoms that are concerning. Last week when getting back into my car from the grocery store it wouldn't start, turned over healthy with plenty of battery..just wouldnt' catch and start. I waited 5 minutes tried again, same story. I then pulled the codes with turning the key to and fro, 12, 11, and 55. I then tried once more and it started up fine. I have realized a slight hesitation when driving on the expressway at 65mph, very slight, feels like a very small slippage and then its fine - almost unnoticeable. This morning when turning left I pulled out into the intersection waited for oncoming traffic to pass and then accelerated, the jeep went for about ten feet and then the rpm dropped to 0 and there was nothing for about 1 second....then caught and went back as normal. I think these small indications could be precursors to a larger issue that might leave me stranded in the upcoming cold chicago winter. Any thoughts or suggestions? I've read through some threads here and a couple things that could be the culprit would be (1)fuel pump, (2) timing belt, (3) IOC sensor?, or (4) crankshaft sensor?? Thanks for any help or suggestions you can provide! I love this jeep and am trying to get to 200K +!

The code that stands out is code 11. Code 11 reads no crank reference signal detected during engine cranking. You don't list your eng as 4.0 or 5.2,but I can say you should change or have changed the CPS as soon as possible. This is common sensor problem and once you code you usually don't have long before complete sensor failure.LOL

Thanks Ronaldk, I was just trying to look for those codes and their meaning. Also it is the 4.0 I6 - I'll get that replaced asap. Is that a fairly easy replacement? Thanks again for your help/

found this - 11 No ignition reference signal detected during cranking OR timing belt skipped one or more teeth; OR loss of either camshaft or crankshaft position sensor.
So possibly could be the timing belt?

Also for anyone else reading here is a good description on how to change CKS and a youtube that may help. I'm going to attempt next weekend....
video:
http://www.youtube.com/watch?v=JoWgHeARguc&feature=PlayList&p=D4F2895D683DE941&playnext=1&playnext_from=PL&index=66

article:
http://www.associatedcontent.com/article/2008830/how_to_replace_the_crankshaft_position.html?cat=27

Ok 4.0 easier then v8. If timing had slipped you could not have run like no problems existed, and you said after problem you got it running again. So change CPS.Your sensor is located on driver side rear of eng on transmission bell housing.LOL

Mission accomplished. It took me the better part of 3 hours to do by myself. I do recommend removing the bracket as shown in the youtube video in order to create more space (the written steps don't include that). The only additinoal advice I would give is to have a good light and..I also had a little bit of an issue removing the old sensor once the bolt was removed, what I found to be easier was to crawl back out from under the Jeep and remove the sensor from under the hood. Also was easy to get the new sensor in. It was a tedious job which took a good amount of time and patience since it's in a tight space with not a lot of visibility. Not sure if this was my issue but Jeep started right up and the test drive was a success....hopefully it resolves the problem. Also one thing I noticed is there was a heat gaurd above the bolt that' snot shown or mentioned in the script. I chose not to reinstall it? so we'll see hwat happens

Thanks for posting back hope your problem is nolonger. My friend has the v8 and trust me thats in a bad place compared to 6.

Ok, so test drive two on the expressway home this evening was a little concerning. I still hear/feel a hesitation every now and then when driving around 65mph. After changing this should I have my timing reset? The symptoms I'm having are:
1) Hesitation that sounds like a small transmission slip when driving around 65-70 mph. This happens every minute or so. The rpm needle doesn't vary much when this happens (maybe 100-200 rpms).
2) When I let off the accelerator the rpms slow and then dive down to below 1000.
3) The idle rpms is at about 500 when idling at a stop light

Any thoughts or suggestions would be helpful.

On another note my oil pressure has slowly getting worse. It used to be 60 when driving and then drop down to about 45 while at idle. Now I'm at 40 when driving and drops down towards 20 when at idle...

Thanks everyone!

Any thoughts??

You cannot set the timing and this is done by the computer only.The part in the distribitor is the part of firing the fuel injectors and you do not want to mess with that.Take the oil pressure sending unit out and insert an oil pressure gauge.See what the oil pressure is while it is running.It could be the oil pressure sending unit or the gauge itself.Scan for codes first if there are any.

Slow idle and hesitation. How many miles since you've replaced the spark plugs? Also, correct me if I'm wrong but doesn't the 96 have plug wires, cap and rotor? I'd replace those as well.

You might also want to check the Cherokee "How To" section, there is lots of info there about the 4.0.