Roughly a month ago I was on my was to school and it was quite cold XJ was running fine but as soon as I got out of the street My 2000 Cherokee died and wouldn't start. I've cleaned all of my grounds, replaced Camshaft position sensor as well as the crankshaft position sensor, all fuses and relays are good however when I check the fuses two of the fuses wont light up with the light probe and causes the "front O2" relay to click when probing, replaced fuses and relays still nothing. I checked the wire harness that plugs into the coil pack and I am only getting 8 volts when cranking instead of 12, yes the battery is fully charged. I have fuel pressure and even tried starting fluid. The XJ turns over. I have replaced the ECU with a brand new refurbished one. I have no idea what to do. Please help me out I really miss the XJ, thanks

 

Did you check if you have fuel pressure at the rail?

 

yes I have

 

I solved the issue, The XJ is running again. I said in the initial post I switched the Crankshaft position sensor (CPS) so i thought it did the trick but boy was I wrong. I decided to buy a higher quality part this time and replaced it again. As a lesson to all of my fellow Jeepers PART QUALITY MATTERS! It was a hard lesson but lesson learned, If you love your Jeep go the extra mile and spend an extra few bucks even if it does happen to work It might not for long and you'll spend more money buying multiple parts.

 

When mine went I went with a Mopar one because of the whole aftermarket bad out of the box thing.
Planning to keep my Jeep forever (LOL) I figure sooner or later some of these parts with not be available.
So I am starting to hoard parts.
I bought a new Mopar CPS to have in "stock". LOL.

 

I just ordered a Mopar CPS to see if that resolves my no start issue.

 

Sigh... Once again have the no start condition. It still cranks but it just doesn't want to fire up. I went to the Jeep dealership just to make sure it would be 100% genuine but it did absolutely nothing. I'm getting fuel to the fuel rail and even tried some engine starting fluid, when the key is in the on position and i wiggle the ECU's wiring connections i hear all the relays clicking and the radiator fan turns on. I tried starting with my foot on the gas still doesnt work, so i believe that rules out the AIC and the fuel since starting fluid didnt work and I have fuel in the rail. I've checked replaced the ASD Relay still nothing. This is my daily with 260K miles so its getting a little hard having to catch rides and borrowing my dads car. I dont have a check engine light but the bulb is good, however im still able to pull the code P1694 I do not have a sentry key, I do not have the no bus on my dash, checked all fuses, battery is brand new, cleaned every single one of my grounds, new refurbished ECU. Please help!!

 

Are all the grounds clean and wiring has good continuity back to battery ground terminal and ECU?

I'm also hunting down a no start issue, so hoping to benefit from your successes.

 

i have not yet checked continuity I don’t know where to start with that. Yes all grounds have been cleaned to bare metal. Same with terminals.

 

Joe, I'd check the wiring on the coil pack. I've been told that it had a tendency to become either bunched/pinched or burned waaaaaay in the back there. If that wiring is not good, fix that immediately. Double check your CPS wiring as well. The exhaust runs right through there and has been known to scorch up the wiring.

After that you need to check for spark. It's a little harder in the 2000+ since it's a coil pack but not a distributor ignition. However there are several rather creative ways to test it if you search YouTube.

Also, if you haven't got a copy of the Factory Service Manual, immediately go to www.cruiser54.com -> Technical Manuals link and download it. There will be a section for testing "crank no start" conditions - that's where I'd go after checking the wiring.

 

Checking continuity alone is not enough because if even one strand is intact, you will have continuity. You should also check the resistance. For example. If a wire has 8 strands, but only 1 is intact, you will have continuity. But the resistance will be high because that single strand becomes a bottleneck. I like to check voltage from end of the circuit to the other as well. A good battery means nothing if the wiring is compromised.

loose connections
dirty connections
broken wiring
chaffed wiring
grounds
corrosion
faulty sensor, etc.

All things to look for. And that corrosion can build up under the insulation where you cant see it. Any exposed wiring is at risk. Battery cables top that list in my experience.