newbie731

Hello All,

I found this forum and I am glad I did. I am hopeful that someone can get me pointed in the right direction.

I have a 1994 Grand Jeep Cherokee. It is a V8 4WD. I've had it for about 2 years and I know the previous owner pretty well and there has never been a major problem or service need for this vehicle in it's history.

SHORT VERSION
Jeep goes dead while in use on road-
Attempts to start fail- will not turn over-
No indication there was a problem. Simple shut itself off-

Please help with troubleshooting likely causes!!!

LONG Detailed VERSION

About 3 weeks ago I was driving into town. I moved from a highway to an off-ramp, everything seemed fine. I slow and yield from the off-ramp and move onto the secondary road, never coming to a complete stop. Once on the secondary road, I'd say a tenth of a mile, maybe, I notice the steering is very heavy and sluggish. I then realize as I am sort of coasting my way up the intersection ahead that the Jeep has shut itself off. Nothing seemed abnormal at all. I never heard it shut off, I never heard any other noises, never felt any vibrations. I am able to get to the red light, I put it in park and began to start it back up and it doesn't turn over. It just winds and winds and winds but doesn't turn over. Frankly it doesn't even attempt to turn over. I would say the starter is engaging though otherwise I'd just hear a clicking noise I assume.

I had it towed back to the house quickly. Just now getting a chance to dive into trying to figure out what's wrong with it without taking it blindly to a mechanic. I am fairly inclined mechanically to do most things I just have no idea where to even begin on this.

Any help, and I do mean any help or guidance on where to start would be so greatly appreciative!

19XJCherokee96

Well...I don't have a zj...mine is an xj. But having sort of the same problem and we're leaning towards the fuel pump. Mine shuts off while driving after about an hour. Once it cools down it, or we put some starting fluid in the throttle body, it starts back up. Might be something worth looking into. But I would start simple if you can. The pump for the zj's are a bit expensive.

newbie731

Problem is once it is shut off it has not been able to be restarted.

I just had someone tell me that my problem is "crankshaft positioning sensor". He said he was 90% sure just based off my description alone.

ol"blue

Welcome to CF. If it died and won't start, or even crank (turn over), and just clicks, it sounds like you may have problems with the battery or cables. How old is the battery? Check the condition of the cables.
Here's how to test/replace the CPS.

kjc

The symptoms you describe do point to the CPS.. When it fails, I believe it shuts off the fuel pump and gets no spark. If it won't start, turn the key to 'on' then check for pressure at the fuel rail schrader valve. Whether there's pressure or not, then i'd crank it while someone checks for fire at the coil. Or just throw a CPS on it.

newbie731

Super information guys. Thank you all so very much.

I will be jumping on this just as soon as my wife gets home today. Will update and let you know what the verdict is!

94zjdriver

I had a simular issue with mine would only wine for ever and not turn over. Bad starter, short verson,
long verson was 8 hours chasing down wires and removing starter, having it tested, reinstalling said starter 4 more hours chasing down wirng finally just replacing starter and no more problems.

newbie731

So, after several hours of forming new curse words and tearing my hands and arms to bits I finally get the old CPS out and get the new one back in. Try to crank the Jeep and it still doesn't turn over.

My father-in-law and began more diagnosing of the Jeep and have found that no fuel is hitting the injectors. We have pressure, fuel is coming through the fuel filter just fine! Not sure what to check next.

Any ideas?

Thanks for your help!

19XJCherokee96

Is it getting all the way to the rail? If so...maybe bad injectors...or clogged fuel line?

Sent from my LG-MS910 using Tapatalk

newbie731

Tech @ Autozone told me that we wouldn't see the fuel anywayz. It goes straight into the combustion chamber . . . he probably knows more than I.

Taking off a plug wire from each side doesn't give us spark. We changed coil pack last night. Still no start from the engine. I hate to wonder about that crankshaft positioning sensor but it's certainly possible they (Autozone) sold me a bad one. I've heard of stranger things.

Going to make sure the pin on the bottom of the distributor isn't burnt out today. After that, I don't know. I guess I need more ideas if anyone is willing to share theirs.

Thanks!

ol"blue

You stated you weren't getting a spark on either side of engine. See if you're getting a spark from the coil. If so, remove distributor cap and verify that the rotor is turning while someone turns the key to crank the engine over. If it is turning, remove the rotor and check it's condition top and bottom for arcing/burn through. Also check the cam sensor/Hall effect pick-up under the rotor. It will cause a no spark condition when it goes bad, but it costs around $50 to replace. Sorry, I don't have the test procedure for it.
If it isn't turning while engine cranks, either there's a problem w/the distributor such as drive gear damaged, or there's a problem w/the camshaft such as the gear that drives the distributor damaged, or cam could be broken along it's length, or the timing chain/gears have failed/broken.

Lawman_745

I just got my 93 ZJ started after 3 other people couldn't and getting it for 200 bucks. Turns out the ecu was bad. Theres not alot that will cause no spark. Firts thing, does the check engine light come on when you turn the key on? That what was wrong with mine. Secondly, do you have power coming to the coil? Check all fuses and relays, espicially the ASD (Automatic Shutdown Relay) and Fuel pump relay. Lastly, check your O2 sensor wiring. My friends XJ wouldn't start due to the power wire grounding to the powersteering pump. That wiring runs in with the crank sensor and ADS. Good luck!

Larset

I would suggest taking it to a diagnostics place. I had similar prob & they told me it was idle control module. Prob seems to be fixed. My Jeep wouldn't turn over & if it did after taking batt out over night & charging & replacing it wouldn't maintain idle just kept stalling. W/all the computers & sensors a diagnostic place 1st will save u $.

newbie731

Update: 02/08/2012

After replacing the CPS and discovering a no spark issue still exist I replaced the coil. Still the engine didn't turn over. I next checked the distributor cap for any burn out. It looked pretty good to me (for what I know). I was then told by an Autozone employee that I may need to replace the pick-up. I removed the distributor a second time to set in the new pick-up and noticed some plastic shavings setting on top of the pick-up, and then noticed what I believe is the starter rotor (black plastic thing sticking up through the pick-up assembly) appeared to be broken off on the end. I took it off and took the pick-up and broken rotor to Autozone exactly as I took it off and when compared with the new starter rotor it was definitely broke off.

SO, I just put on a new pick-up, new starter rotor and new distributor cap. I tried starting the jeep and it still did not crank; however there was an obvious difference this time because I thought for a second the engine was really fixing to start. I mean it was as close to starting as you can get. And much closer to starting than it has been since it first went dead.

Finding the starter rotor was broke off is the first real thing that I've found as evidence of a problem. I felt for sure this was the problem. But, given the jeep still didn't crank has me left even more lost than I was. I assume a broken starter rotor would keep the jeep from starting but now that I have replaced it - where do I go from there? With everything I've done with the coil, the CPS, taking the plug wires off and on and replacing the distributor, pick-up, and starter rotor is it possible I've blown a fuse or screwed up a relay?

Lawman_745

Are you getting power to the coil? Check for power at the 2 wire connector going into the coil. Is the check engine light coming on when you turn the key on?