Matts Jeep

my '98XJ wouldnt start this morning. I know that it has a problem with the NSS but it used to start in either Park or Neutral. So i could always get it started one way or another. But this morning i went to start it and it turned over but never fired up, and after about 30 seconds it would even do that in either gear. Nothing! so i get home tonight and try to start it and it did the same exact thing it did this morning...any ideas??

DFlintstone

I know on my older Renix jeep, if the battery is going it will crank mostly OK, but still might not start. Not sure about yours. A quick way to rule that out is jump it. If that does it get your battery tested.

Of course you would want to check for spark and fuel. A fast way to see if it's not getting fuel is to try starting fluid. If it starts, fuel problem. You should hear your pump run a second then you turn the key to on. and here's this;

If you hold the key over, and jiggle the shifter in park or neutral and it starts, it's your NSS. http://bc4x4.com/tech/2010/jeep-neut...ty-switch-nss/

Nss won't keep it from starting if it's cranking.

Buy/borrow/rent a code reader?

tjwalker

Let's review so there is no confusion. So does it actually turn over or does it not turn over at all?

If it doesn't even turn over and your were having NSS problems which you were, it is very likely that your NSS finally failed catastrophically. Either way, you should resolve the NSS issue or it eventually will leave you with a no crank condition. Refurbishing often returns full function.

http://bc4x4.com/tech/2010/jeep-neut...ty-switch-nss/

If it turns over but doesn't START, then you must follow the no-start protocol, of which job #1 is to check to see if you have spark at the spark plugs. Pull a plug, keep it attached to the plug wire, place the plug electrode near a good engine ground, have a buddy crank the engine while you watch. You are looking for a strong, BLUE, snapping spark. Yellow/orange/white indicates a weak spark, which may not be strong enough to start the engine.

Matts Jeep

I tested it and its getting fuel so we can ruel that one out. But i put a light tester on the spark plug wires and it showed that there was no spark at all. so its not getting a spark, and today it gave me a code PO320. I looked it up and it has to do with the Ignition/Distributor Engine Speed Input Circuit Malfunction. An i found that it has to do with the Crankshaft Position sensor. went to the auto parts store and picked one up...gonna try that tomorrow. ill keep you posted

DFlintstone

Boy, there's others here that know better than me. (TJ for one). Code sounds right I guess. Do check the plug/wires, to the CPS.

You wanna lay with your feet going under the passenger side so you can reach up the front with your left, and work the wrench with your right, which will be back near the cross-member. Don't know if you are torx or 7/16, (11mm). A trick is to tie a long string on the plug when you remove the old, then use it to pull the new back up. It's really pretty easy, the second time you do it!

And check this out....have fun!

On YOUR CPS, I recently found this link on testing the later, OBD II CPS, which may well apply to yours. I haven't tried it, don't know anyone who has. It looks like he's verifying 1/2 a volt, (aka.5v or 500 Mil.Volts), presumably AC, (with a true RMS meter), (back-probing, with it connected), at his third (Red) wire. (not the ground, and not the 5V-DC sensor feed). I don't know what % difference I would expect from my "cheap-o-meter", as opposed to the true RMS, but it might not be much. http://www.cherokeetech.com/VBull/sh...agnosis-Videos

F1Addict

And while you're under there, might as well pull your NSS and clean it

tjwalker

Do yourself a favor and buy your crank sensor directly from the Jeep dealer. No lack of issues with some (not all) aftermarket crank sensors. Why take that chance?

Matts Jeep

Thanks for all the help guys. Yep i replaced the crankshaft sensor today and its running again. didnt have time to clean the NSS but definitly will as soon as i get a free minute. Thanks again, all the info helped out a great deal.

DFlintstone

Hey , far out. Sounds like you pretty much handled it yourself, we were just "emotional support"!..Glad to hear you got'r goen..