Jeep won't start

Well, I started my jeep but after it was running for a min or two i turned it off to go grab something. I went back to start it and nothing. My lights work but when I turn the key nothing happens. There was no hesitation when it started the first time. I am not even hearing the starter kicking in. I am assuming my starter when bad but I am not sure. I tried jumping it but that didn't work either. The battery is an optima red top that is only a few months old.

1st not mod tech

2nd Crawl under it and hit the starter with a hammer a few times. If it starts, then your starter is on its last legs.

Same thing happened to me a few years back and it turned out my crankshaft position sensor quit working and needed replacing. It is a common thing when they get abit older, that could be the problem.

Could be a neutral safety switch.

X2 to both...as i've had both happen.

Take something long like an axe handle and follow the cable on the back of the engine down to the CPS on top of the transmission. Move the little box of the CPS around and see if it starts.

For the NSS, while turning the key to start the vehicle, push the gear selector forward in Park very hard. If that doesn't work, ease it back slightly (again with the key turned). If it tries to start, that is your problem.

Common, pesky problems for XJ's.

I already ruled out my starter since i just put a new one in. I will see if its the NSS first then I will try the others. About how much do those sensors run

I changed mine anout 6-months ago and I don't remember exactly how much it was. I want to say it was like $25, but I could be mistaken. It would be a simple swap if you could get at it. You get to twist your arm up and around everything and then make like 1/16 turns on the bolt. On the positive, it really made a big difference in starting and running after I changed it.

I just read your post again and I realized that you were asking about the NSS, not the CPS (which I was referring to). Don't buy a NSS, as they cost like $140 and they are cleanable, which is what I did. If that is the problem, take it off and take the cover off. They get all gummed up with grease and grime and then the copper contacts won't touch. Clean it up with some solvent and then pack it with dialectic (spelling?). When you put it back on, you just have to make sure you adjust it correctly. I don't remember exactly what the trick was with that, but I got the info off of , so it shouldn't be too hard to find.

Like the CPS, once I fixed this, it saved me a ton of aggrevation. The first time my NSS acted up, I had taken my wife's car and she took the kids to school in the XJ. When she tried to leave, it wouldn't start...I'm sure you can guess how her phone call to me (and the rest of my day) went.

Good luck!

I have never seen a CPS stop a motor from turrning over, starting yes, but not from turning over. I lean more towards a NSS or starter.

If the starter is new, CHECK YOUR CONNECTIONS! I know from experience ... beyond starting in park a NSS should start in Neutral also.

Kevinma255 said:

I have never seen a CPS stop a motor from turrning over, starting yes, but not from turning over. I lean more towards a NSS or starter.

If the starter is new, CHECK YOUR CONNECTIONS! I know from experience ... beyond starting in park a NSS should start in Neutral also.

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X2, the CPS will keep the fuel injectors from firing, but it will still turn over.
My NSS had just started to go bad before I parked my XJ. I almost always had to start it in neutral.
Also, don't rule out anything just because you recently replaced it, you may have gotten a defective part.

IIRC, when my CPS went, it wouldn't turn over or anything... Replaced it, and it fired right up... maybe my experience was just an oddball occurence, but that is how I remember it....

Try what these guys are saying, I can't think of anything more off the top of my head that would be relatively quick/easy fixes...

5spd_xj said:

IIRC, when my CPS went, it wouldn't turn over or anything... Replaced it, and it fired right up... maybe my experience was just an oddball occurence, but that is how I remember it....

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Must have been an odd occurrence, you can go unplug it, and I bet it will crank. The circuit to the starter motor is simple, and has nothing to do with any sensors other than the NSS.

A quick, semi-redneck test to see if it's before the starter, is to crawl under the jeep and short out the main 12V and the smaller "trigger" wire at the solenoid (built onto the starter). If it cranks, it's something in the ignition circuit, if not, it's the starter. Make sure to test for voltage as well just in case it's the main power wire.

innnnnnnnteresting.

TRAILREADYXJ said:

don't rule out anything just because you recently replaced it, you may have gotten a defective part.

Click to expand...

Even if this turns out not to be your problem (check NSS, connections, etc to start with) truer words have never been spoken....

There is always a chance, albeit a slight one, that a new part will either not work on installation, or they can fail soon after it is installed so never rule that out when in the repair process.

I worked in Test Engineering for 23 years for a company that among other types of specialty semiconductors, provides electrical sensors to the automotive industry; these types of failures occur more frequently than you might think, even with stringent quality control and reliability testing.

1. A part that does not work right out of the box is put into the category called "DOA, or dead on arrival"

2. A part that fails soon after installation is put into the category called "infant mortality"