1999 Cherokee XJ Limited 4x4. Was driving down the road and it just died, and wont start. Wants to start, but wont turn over. I've been told Crank position sensor. When I looked up symptoms of a bad CPS, I had a few. The only ones I had were REALLY bad gas mileage, has really low power (slow acceleration) and its died and wont start. I also noted that the gages didn't work for a bit after it died. I got it towed home. Any advise on this? And help would be greatly appreciated. Thanks

 

do you have spark?
are your gauges normal?
a cps wont play havoc with your gauges?
do you have a obd2 scanner? ... get one you are going to need it

 

My research when mine went did indicate weird gauge crap.
Though I did not have any of that.
No CEL either.

Have you tried to start the Jeep since you got it towed home?
My experiences with it here:

https://www.cherokeeforum.com/f2/cut...riving-241745/

 

will it mess with the fuel pump? The fuel pump is making a weird noise, and it doesn't turn off. Never did that before

 

Never heard that before concerning the CPS so....

 

I have done this one twice. Have a Napa cps at the moment but when I get some extra cash going to switch to a mopar. Your problems are EXACTLY what my 99 sport did. Really hard to start sometimes, died at stops finally just would start at all.

 

When I turn the key to accessory, the fuel pump keeps running. Only turns off when I turn key back. Also the fuel pump relay is making a constant clicking noise. I'm beginning to think I have big problems

 

Is the engine cranking? Check for spark and check for fuel.

 

My suggestion is before buying any parts, you go through and renew your grounds. Take them off and clean them the old fashion way with brushes, steel wool etc. Don't just use a spray. Check your battery cables for corrosion under the insulation. Make sure your battery is good, have it tested at an auto parts store.

These Jeeps do strange things when they are not grounded correctly.

The two main grounds are the B- post to the fenderwell, and the B-post to the block, right under your coil. That fenderwell ground is often flaky. The one under the coil less so, but both should be taken apart and cleaned down to shiny metal. Don't rely on a visual inspection.

There's a ground from the rear of the head to the firewall - a braided strap. That's just for suppressing radio noise from the injectors firing. Some people replace it with a big fat battery cable. That's a complete waste of money. The standard braided strap is more than enough on that one.

There's another near the oil dipstick, too.

Don't overlook the cables themselves.

As mentioned, the alternator itself grounds through its case to the mounting points. Not likely to be a problem, but it doesn't hurt to clean things up.

If that doesn't take care of it, then you are going to have to clean wiring harness connections, but you might not have to deal with that....yet..

 

Bingo. This is where you start.


(But it's "old fashioned", not "old fashion". Kind of like it's iced tea, not ice tea, or shaved ice, not shave ice.)

 

Yep, mine did same thing, I chased the fuel pump, regulator and injectors for a few days, took it to a mechanic friend and he laughed at me and put a cheap cps he had on it. ran great for 2 days the died again and I put a Napa one on it. I can't tell you that's it exactly cause im also fixing small vacuum leaks and my exhaust was rotten at the time and now im waiting on a new o2 sensor that I think will get it back really right at idle.

 

Something similar happened to me and I several mechanics couldn't find out what was wrong, it happened to be the transmission wiring harness because it has the cps on it. One day the last piece of insulation peeled off and started shorting on the other wires. He put liquid tape (I mainly wanted a diagnosis), Then I later went to the junkyard and cut out a harness and soldered it on to mine, you could repin if you wanted. check your wires? The xj gets really hot and your xj is at least 19 years old so needless to say a lot of connections could be frayed or damaged especially in Texas heat.

 

Hey so I bought this 92 XJ Laredo 4.0L and I have no clue on what to do anymore. The car has a very bad rough idle and will die and restart itself. The car has a bad knock on idle but when I’m accelerating the knock goes away. Sometimes the car will just die, and the gauges will fluctuate randomly. The oil pressure and Rpm gauges will randomly move on its own. Sometimes the car will not crank and will do a long crank and I have to press the pedal before it to turn over a lot of the time. The car knocks I’ve changed the fuel filter Right before I recorded this video and the car still overheated and died on me. LI recently replaced the thermostat, and tps as well. I have a code for the tps even tho I just changed it. I have no check engine lights when I’m driving. The only time my CEL ever came on was once and it have me a code for the speedometer. Please help I’m all out of ideas

 

When you take apart, clean, and replace all the grounds, remember to do the same thing to those four freaking wires that ground to the dip stick stud.

 

I am curious which Napa CPS you bought and how long you have had it in the Jeep.
We sell 3 different ones. The NOE, MPE, and Echlin line ones.
I work there and was thinking about using the Echlin one when mine went bad.
Went with a Mopar one instead cause of all the bad out of the box threads with aftermarket ones.
Usually guys talk about Auto Zone and Advance Auto ones when it comes to this.
Am curious if Napa ones might be better then other auto part store ones.