Jeep Dies, No Crank condition

[Anadaron]

I have thoroughly searched the forums and other places but cannot connect the two issues to my satisfaction.

Background Info: 1998 Jeep Cherokee Limited, AW-4 transmission, 4.0l I6. Went wheeling 3-4 days ago took it through alot of mud puddles, mud and various other adventures. No problems prior to this related to starting.

Problem: Jeep started just fine this morning as always and i drive to Starbucks for my overly expensive coffee. Come back out after 15 minutes I get a no start condition from the Jeep, as in no crank, all lights come on, fuel pump primes. Turn key on and off 3-4 times, sit frustrated for a minute or so considering options try to start it again and it fires right up.

Drive around making numerous stops, turning jeep on and off with no issues. Come around a round-a-bout and jeep dies like i cut the ignition off and once again have a problem with restarting it but after 3-4 attempts it fires up. Figuring a possible fuel issue because i have 1/4 tank of gas i go and fill up. Go back to same round-a-bout and jeep dies again. This time instead of stopping i drop it into neutral and it fires right back up.

Go to school come back out after an hour an i get a no start, no crank all electronics working fine condition again. This time no amount of turning the ignition on and off works. I call a friend and he suggests moving the gear selector through the gears and trying again. I perform this and the jeep starts right up.

Conclusions: I have read everything about NSS failure and the need to clean and reinstall the sensor, but no where in those posts have i found a situation where the NSS failures causes the Jeep to shut off as if turning the ignition off. Because of this i am hesistant to decide ti is just the NSS and not something else, i.e. the igntion switch, that is causing this issue.

Any input is helpful, this is my first jeep and i have had it less than a month and abosolutely love it. Please help me fix this issue.

[jeepster_259]

check under the hood and make sure you fuses/relays in the black box by the battery are not wet. If you were going through deep water, those could've gotten wet. Happened to me on my 98. I unplugged everything and let it sit for a couple days to dry. Do you have reverse lights? If your NSS is bad, you won't have reverse lights, quick way to diagnose that. Also, does you ECM by the airbox have a rubber plug in the back of it? I found out the hard way that you need to have that rubber plug or you'll get water inside your computer and that's the end of it. Just some ideas to check.

[MTBracer367]

go and take your battery terminals off and take the wires off of them and clean the hell out of them the same thing happened to me the other day in my 98 at walmart (which is very close to starbucks where i come from)
i guess mud gets in there and the starter doesn't get enought power to it i did that that day and have gone muddign several times since and have had no issues relateld to that

[Anadaron]

Will a faulty NSS cause the jeep to cut off, as if turning the ignition to the off position? I am sure my no start conditions come from a gummed up NSS because i can move the gear shifter and it fires right up. I will get it cleaned up and reinstalled.

But can this sensor also cause the cut off i described or is that another issue to look into?

[bigalpha]

Originally Posted by Anadaron

Will a faulty NSS cause the jeep to cut off, as if turning the ignition to the off position? I am sure my no start conditions come from a gummed up NSS because i can move the gear shifter and it fires right up. I will get it cleaned up and reinstalled.

But can this sensor also cause the cut off i described or is that another issue to look into?

The NSS is there to make sure you can only start the Jeep in 'P' or 'N'. When it fails, you are able to start the Jeep in another gear. I don't believe that the NSS can cause the symptoms you are experiencing.

During those times the Jeep shuts off and you try to restart it unsuccessfully, does the engine turn over, or does nothing happen?

Thinking maybe a possible CPS.

[Anadaron]

Nothing happens.

[bigalpha]

I'd have to say CPS. Pull it and clean it well. Then reinstall.