96 4.0L Won't Start

First post here guys. And I do realize there are probably a blue million threads on this same subject. I tried searching, but for some reason my tablet don't like that, so here goes.

Bought my first XJ a couple of weeks ago. 1996, automatic 4 speed, 4wd, 91000 and some change on the clock. The guy I bought it from said that it would take spells where it wouldn't crank. Found out today what that meant. Full electrical power or it seems, but the starter acts like it wasn't getting voltage.

The guy I bought it from said that he had it at a mechanics a couple of times but to no avail. From what I have been able to find on the web, it could be a couple different things. Ignition switch, or neutral safety switch. The ignition switch has been replaced according to the guy I bought it from and it has a new key. I'm not sure if the electrical part or the connecting rod between the key and switch was replaced.

So today when I go to leave work, nothing doing on the cranking front. I tried giggling the shifter to neutral and park, nothing. Tap on starter solenoid. Nothing. So I had read something about a Crank Position Sensor, so not knowing if that would cause a no start, I unplugged it. I also disconnected the battery. Left them both for about 10 mins. Connected every thing back up, and bam sucka, it started right up.

That's where I'm at. After getting home, fired up every time. Any thought or suggestions would be greatly appreciated

Inspect the connections on the starter, the connector/junction block tends to fry. Usually because the last guy that working on it didn't tighten it right.

Battery clamps, shinny clean, free of oil and grease, moderately tight.

Starter brushes get worn or are covered in oil or mud. If the outside of the starter is oil soaked, the oil can find it's way inside the starter. Usually a leaky oil filter adapter is the culprit. Sometimes muddy water gets inside the starter, when the water evaporates it leaves crusty mud.

The starter needs to spin up for the solenoid to completely engage. Worn or dirty brushes can make the whole process iffy. You may not hear a solenoid click, even though the solenoid is OK.

Tapping on the side of the starter, near, but not on the base sometimes helps the brushes seat for one more start. Whacking that sucker too hard and you may damage it seriously.

The starter relay is seldom an issue, but just to eleminate it you can switch it with another relay (not the fuel pump relay) .

Solenoids very rarely screw up. I've had a new one sitting on a shelf in the shop for 25 years, never needed it on any of my XJ's.

The solenoid wire running down the side of the block is kind of an afterthought and doesn't have much protection. Won't hurt to check it for rub throughs or whatever.

First off it could be the battery, or the contacts at the battery, corrosion, loose connections. Same goes for the ground cable to the engine block and hot cable to the starter solenoid on the starter itself. The Starter solenoid maybe used up, burned contacts from age, or the starter motor brushes may be bad and on their last legs. Or both, or all of the above.

CPS has nothing to do with it.

There is an easy way to test the starter and solenoid with a screw driver by jumping the contacts (by passing the ignition switch in one case, and by passing the starter solenoid in the other case). Try to google a you tube or photo write up in how and where to do that, the contact points.

Yes, dirty contacts on the NSS and a bad or misaligned ignition switch can cause no cranks.

8mud, does the 96 have the little old style relay near the battery that the Renix has? I had to replace one a year ago for no crank situations.

Interesting I have gone through several starter solenoids (on the starter) on jeeps and other beasts, almost as often as starters them selves.

8Mud said:

Solenoids very rarely screw up. I've had a new one sitting on a shelf in the shop for 25 years, never needed it on any of my XJ's.

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The starter relay is in the PDC and the wire from the relay that connects to the solenoid wire near the PDC is tiny, like 16 gauge.

There is a kind of connector that combines the battery plus connection and solenoid connection. Might make it difficult to try and jump it.

If you do try and jump it always be careful with the threads. Melting the connection bolts/studs can make it difficult to remove the nut.

Thanks for the replies guys. I should have mentioned that the battery is brand new. Also like I mentioned before the guy I bought it from said that it would take spells of not starting. It was really weird, turn the key, all functions would work except it wouldn't turn over. I'm thinking I'll take the ignition switch apart to have a look see. I've only had it on the road for a few days, and this was it's only hiccup.

Much easier to take the starter out, mark the position and remove the end cap from the starter. If the wire running to any brush is hitting the top of a brush holder, the brush is too short. Worn brushes can make starter function a hit or miss affair.

Putting the end cap back on is a pain but doable. Easier with two people, so you have somebody near to hear your cussing and maybe try to help some.

The only thing you really have to watch out for is to remove only the end cap and not pull the case with it. If that happens no panic just look carefully how it all goes back together. On some starters there is a thrust washer at the end of th shaft, on others there is a single ball bearing. Whichever it is, a little dab of grease will keep it in place during reassembly.

Ecomike said:

Interesting I have gone through several starter solenoids (on the starter) on jeeps and other beasts, almost as often as starters them selves.

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Far and away the most common starter problem is the brushes.

I did clean the water and rust out of one solenoid, smeared a little Vaseline on the piston and reassembled. Did that around twenty years ago and it still works fine.

Got around to taking the starter apart yesterday. Brushes looked good. Some carbon inside, so I blew it out. Scotch brighter the brushes, and contact points. Cleaned up terminal ends, grounds, and battery contact points. I guess time will tell. Thanks for the replies and help. Awesome forum here!