Turns over but won't start

[Tommy4949]

OK, I search the firs 10 pages that came up when I searchedfor my subject line. It started and ran just fine yesterday when I moved it. Now it won't start. It seemed like it was going to start at first, but cut off immediately after turning the key back to the run position. I can her the fuel pump kick on like normal and then shut off after it reaches pressure, but it just turns over and over and doesn't run. It's been snowing and sleeting for the last 15 hours and is supposed to continue until tomorrow morning, so I can't check it until tomorrow sometime after I dig the 2 feet of snow out from around my Heep. I am unfamiliar with no-start issues as I have never had a problem in that department. What could cause this to happen suddenly over night? Thanks, I'm in a real bind as I need to go somewhere and I have no ride and no other vehicle to drive for a few days. Thanks for any insight you guys can offer.

 

[8Mud]

First thing to do is figure out if you have spark or not. If you have spark, see if it is strong, weak or intermittent.

 

[xjtrailrider]

CPS(crank position sensor) most likely, Its located at the top of the bell housing, drivers side. Follow the pig tale lead up the firewall to the plug. Unplug that and plug it back in and see if it will start. You should plan on a replacement, that trick will only get you a few starts.

You will need, or should I say, I use a 3' 3/8" drive extension and a 11mm swivel socket to remove it and go in from underneath. I drop the new on in from the top and use "bubblegum" to hold the bolts into the swivel socket to re-install. It takes patience but you will get it!

 

[Tommy4949]

CPS(crank position sensor) most likely, Its located at the top of the bell housing, drivers side. Follow the pig tale lead up the firewall to the plug. Unplug that and plug it back in and see if it will start. You should plan on a replacement, that trick will only get you a few starts.

You will need, or should I say, I use a 3' 3/8" drive extension and a 11mm swivel socket to remove it and go in from underneath. I drop the new on in from the top and use "bubblegum" to hold the bolts into the swivel socket to re-install. It takes patience but you will get it!

Thanks, I will give that a try. So it will go bad all of a sudden like that? What causes this to go bad?

 

[xjtrailrider]

Thanks, I will give that a try. So it will go bad all of a sudden like that? What causes this to go bad?

It quits picking up signal from the tone ring on the flex plate/flywheel. Like most electrical things they just do not last forever. It sometimes can be a bad connection at the plug or a combination of the 2. If the trick doesn't work then the CPS is most likely done but like 8Mud said, it could be something else.

5-90, OLD MAN, or 8Mud can give a more technical answer than mine!

 

[Bored400]

wear, time, heat...check your spark too though and look for any burned wiring.

 

[Tommy4949]

Thanks guys. This couldn't have come at a worse time, weather wise. I knew this would happen. I just got my 2000 Grand Prix back on the road after about a month and a half. I figured I would start having problems with the Jeep now, I was right. For the last two years, I have constant problems with one of my too vehicles, but not both at the same time. Within a week of fixing something, something else goes bad, FOR TWO YEARS STRAIGHT!!!

OK, rant over. Thanks again guys.

 

[Tommy4949]

OK, I search the firs 10 pages that came up when I searchedfor my subject line. It started and ran just fine yesterday when I moved it. Now it won't start. It seemed like it was going to start at first, but cut off immediately after turning the key back to the run position. I can her the fuel pump kick on like normal and then shut off after it reaches pressure, but it just turns over and over and doesn't run. It's been snowing and sleeting for the last 15 hours and is supposed to continue until tomorrow morning, so I can't check it until tomorrow sometime after I dig the 2 feet of snow out from around my Heep. I am unfamiliar with no-start issues as I have never had a problem in that department. What could cause this to happen suddenly over night? Thanks, I'm in a real bind as I need to go somewhere and I have no ride and no other vehicle to drive for a few days. Thanks for any insight you guys can offer.

Well, I went out this morning and it started right up. I ran it for a good hour or two plus started it 2 or 3 more times with no problems. I don't know what was going on with it, but I'm going to get to the bottom of it. What does the problem sound like now that it is suddenly working again. I tried about 3 or 4 times to start it yesterday.

 

[BruceB83]

Well, I went out this morning and it started right up. I ran it for a good hour or two plus started it 2 or 3 more times with no problems. I don't know what was going on with it, but I'm going to get to the bottom of it. What does the problem sound like now that it is suddenly working again. I tried about 3 or 4 times to start it yesterday.

Yup, that sounds like the CPS. It can be a real gremlin causing you to be constantly scratching your head if you don't know about it. Replace it and call it a day.

 

[Tommy4949]

Well I'll be, that thang ain't cheap.

 

[xjtrailrider]

Well I'll be, that thang ain't cheap.

I know and I carry a spare in each of the 5 XJ's and the tools to change it! It is one of the few achiles heels of the XJ, YJ, TJ, ZJ line up

 

[Tommy4949]

I know and I carry a spare in each of the 5 XJ's and the tools to change it! It is one of the few achiles heels of the XJ, YJ, TJ, ZJ line up

Wow.

I tested the awesome thing according to AllData and it tests just fine. Is it one of those parts that fail intermittently and it will only fail the test when it won't start, but pass when it will start? Is there any way to bypass it like the NSS if I need to? I just spent all my income tax money on bills and fixing my other POS, I'm not sure when I will be able to buy the CPS. Plus the parts store doesn't stock it and it will have to be ordered.

I'm really curious about a temporary bypass of the CPS, thanks.

 

[Saudade]

There is no way to bypass the CPS. It tells the ECU when the motor's at TDC in order to fire the ignition. Yes, it can be intermittent. If so, your only recourse is to change it.

They are less than $35 at Autozone. Maybe cheaper elsewhere.

 

[dj's 2000 xj]

Check the wiring to CPS beside the firewall. Mine did this and when I checked the wire route the day I was going to change it, I saw where the exhaust had melted the wiring and caused a short. 5 minutes later and I was back on the road. All I needed was a good splice, now I have a spare CPS for my 88

 

[Tommy4949]

There is no way to bypass the CPS. It tells the ECU when the motor's at TDC in order to fire the ignition. Yes, it can be intermittent. If so, your only recourse is to change it.

They are less than $35 at Autozone. Maybe cheaper elsewhere.

It's $55 at Advance Auto Parts where I'm from, even online. So I guess I will just have to plan on changing it as soon as I can. Is there another way to get it to work like the guy above saying to unplug it and plug it back in?

 

[Saudade]

You can certainly try it. If that works then the issue is likely corrosion in the connector. You may be able to clean it out. Make sure the harness is intact (no breaks, burns or exposed wires).

 

[xjtrailrider]

Wow.

I tested the awesome thing according to AllData and it tests just fine. Is it one of those parts that fail intermittently and it will only fail the test when it won't start, but pass when it will start? Is there any way to bypass it like the NSS if I need to? I just spent all my income tax money on bills and fixing my other POS, I'm not sure when I will be able to buy the CPS. Plus the parts store doesn't stock it and it will have to be ordered.

I'm really curious about a temporary bypass of the CPS, thanks.

They fail at very inopertune times, so I always have one with me. Its the one thing that will leave you stranded in a XJ.

 

[cambosoup99]

bad camshaft position sensor in the dizzy also causes the same sypmtoms.

 

[8Mud]

Quadratec has them for around $20

 

[Tommy4949]

bad camshaft position sensor in the dizzy also causes the same sypmtoms.

What does that mean?