Won't start...

[XJTodd]

I just remembered that I have also noticed that my speedometer has been kinda bouncing around while driving at a constant speed. It tends to bounce downward more than anything maybe 5 mph or so, and it's intermittent. I know that my speed certainly isn't changing that fast, or I'd certainly be having some neck issues by now.

Could this be related in some way? Or should I add this to my list of WTFs?

 

[Stang5lgt]

Huh you might have a charging issue. The speedo is electronic. They bounce when the voltage is low. If you have volt meter let the jeep idle and check your voltage at the battery. Should be 13.5 plus on the volts. If not you are running on battery most of the time.

 

[Stang5lgt]

That might explain your dieing problem too.

 

[Skully]

That might explain your dieing problem too.

Stang has a point........if you alternator isn't putting out the juice your motor won't run right. Specially with fuel injection requires more power than a conventional carb. What did your alt. meter read when she was still running?

Try your grounding like Stang mentioned earlier. You would be amazed that what a bad ground can effect.

 

[YELLAHEEP]

A "bouncing" speedometer can also suggest that the speedo gear may have backed away from the gear inside the t-case. Just to rule it out, I'd check to see if the Speed Sensor and gear are tightly fastened in place.

An inconsistent speed signal could certainly cause driveability issues..... but I'd have to think that it would most certainly set a CEL. :dunno:

If it were a ground issue, I'd think he'd be having more than just speedo issues. His radio, fans, lights, etc. would also be having problems.

 

[Skully]

A "bouncing" speedometer can also suggest that the speedo gear may have backed away from the gear inside the t-case. Just to rule it out, I'd check to see if the Speed Sensor and gear are tightly fastened in place.

An inconsistent speed signal could certainly cause driveability issues..... but I'd have to think that it would most certainly set a CEL. :dunno:

If it were a ground issue, I'd think he'd be having more than just speedo issues. His radio, fans, lights, etc. would also be having problems.

He might not even realize other issues if it in fact is an electrical issue. Coming from a computer background and working on computers I found that replacing a power supply would fix a lot of weird lock up issues even if the computer seemed fine. Put a power tester and found bad / inconsistant power output.

The XJ's entire motor is controlled and ran by sensors and electrical connections. A bad ground or bad output power can cause sensors and the "Computer" not to run right or run at all. Personal experience with my '90 XJ by cleaning the main grounding strap from the motor to the firewall and adding a second ground off of the battery to the firewall solved my stalling problem and I found my radio had better radio reception (Not kidding I knocked it off to a factory crap radio) brighter interior lights......

Just a thought............

Speaking of speedo cables, mine did the same thing and reached underneath my dash and found it had vibrated loose and once I tightened the coupler, no probs

 

[XJTodd]

Voltage looks like it always has. I drove it again this morn to see if I noticed anything related with the voltage vs speedo. Nothing correlating. I haven't checked the speedo cable connection though.

Voltage meter looks as it always has, solid at 14:

 

[Skully]

Voltage looks like it always has. I drove it again this morn to see if I noticed anything related with the voltage vs speedo. Nothing correlating. I haven't checked the speedo cable connection though.

Voltage meter looks as it always has, solid at 14:

Hmmmm..........did you have the no start issue and try what Yella suggested?

Have you disco'ed the battery and reset everything? You get no code but it won't start intermittently but still cranks right? ......try the TPS.

Threaten it with a BFH or that you will trade it in on a new JK

 

[XJTodd]

Hmmmm..........did you have the no start issue and try what Yella suggested?

Since that day it happened on the road, I've only driven it..well 3 times including this morning. The first time it was just to move it in the garage, and it died on me while backing up the driveway. The 2nd time was last weekend to go run those errands, and after messing around with the CPS as much as I could, and it seemed just fine (other than that wierd speedo thing here and there). But it hasn't died on it's own to test with.

Have you disco'ed the battery and reset everything?

I haven't done anything with the battery yet.

You get no code but it won't start intermittently but still cranks right? ......try the TPS.

It hasn't faild to start on the first try since day after it died on me on the road.

It sounds like I'm not going to damage anything if it goes kaput on me driving around. Worst case it takes up some time to deal with it on the side of the road, but at least that way I might be able to troubleshoot it easier if I know something is definitely not working. So I think I'll just give it a bunch more use over the next week or so and see what happens. I just sucks that I can't trust it to get out on a trail one more time before mountain winter arrives.

Threaten it with a BFH or that you will trade it in on a new JK

Yeah, I did that once, and it didn't fix the problem, so it knows now that I'd be crying wolf. I could try the JK thing I suppose, but if follow through on that my wallet or wife hears about that, they may retaliate on me.:twak: Solitude in the garage didn't help anything either. Maybe if I buy it something fancy it will behave a little.

 

[Skully]

You getting good consistent fuel pressure?

I think a new TPS is like $30-$40 from NAPA?

You traced all your wiring to see if you have a kink or frayed wire somewhere? I have had problems in the past with intermittent coil problems......... Don't know man.............. I hate scenarios like this cause you are not exactly sure what it is and spending money randomly to attempt to fix it, if you can afford it take it to a stealership and maybe they can figure it out faster.

There is no one on this board that has had a similar issue?

Maybe you should change your plan and take it out for dinner and buy it some jewelry or something? :laugh3:

 

[Skully]

Sent you a PM for a guy that works on our company fleet, he is a mobile mechanic and from Greeley.

When I chatted with him for a brief second this is what he suggested for you to do.

the CPS would just fail and won't run until replaced just like Yella mentioned.

It sounds like wiring.....next time it doesn't start have someone crank it over and check to see if you are getting spark to the plugs. If you are then it is a fuel issue more than likely. If it is not sparking it could be multiple things. He worked on several XJ's that had similar issues and on one it turned out to be the main wiring harness had somehow come partially loose and over a short time developed corrosion on the connectors and turned into an intermittent problem similar to yours.

He had another one the wire to the MAP sensor was slightly cut and worked its way to intermittent contact.

Hope that helps a little.

 

[ColoradoRaptor]

This isn't a CPS problem. When they go, they go and it won't start again until the sensor is replaced.

Occasional problems like you're having suggests the Throttle Position Sensor. They can act up and not set a CEL (check engine light).

Again, if you get the no start situation - try pressing the accelerator to the floor. If it starts after doing that, my money's on it being a bad TPS.

You are wishy washy first you agree that it could be a CPS in post 6 then you just change your mind and say NOPE not a CPS............... I still say the CPS could be the culprit but like most everyone here it is just a shot in the dark! If not the CPS then the fuel pump would be my next guess.............:dunno:

 

[YELLAHEEP]

Next morning when I went to leave, I couldn't get it to start at all and havne't since.

I'm assuming it cranks the engine, but it won't fire up?

Have you pressed the throttle to the floor while cranking? Does it start when you do that? If so, it's likely the Throttle Position Sensor (TPS) which is on the back (firewall side) of the throttle body.

If you get nothing using the throttle, check for spark. If no spark, then it's likely the Crank Position Sensor (CPS) which is located on the driver's side top of the bell housing. Pain in the ass to get to.......

You are wishy washy first you agree that it could be a CPS in post 6 then you just change your mind and say NOPE not a CPS....

Try reading EVERY word before jumping to conclusions ya :looser:. Sounded like he had a NO START issue at the time, not something that would run, then not run. I was explaining that with a NO START situation, it certainly could be the CPS and to check spark to confirm.

In my later post, I read his post describing the symptoms more clearly (said it runs but dies unpredictably) and since that wasn't a NO START condition, I posted that it couldn't be the CPS - because the CPS won't allow the engine to start when it goes bad.

XJTodd: Could you try posting slower so 'Raptor can keep up? Thx!

:twak:

 

[Fred]

My Renix would die intermittently and unexpectedly, and it was fixed by replacing the CPS. If fact, twice in the last 16 years. Whether that applies to a 2000, I couldn't tell you.

Ask how many people's jeep I started on the Eagle Run trip by plugging and unplugging the CPS from the harness? Two for a fact. Neither of them were a 2000, but I think one was an HO.

Those experiences would seem to contradict you.

Fred

 

[YELLAHEEP]

Well then slap my ass and call me Sally. Apparently I don't know shit.

Nor do I care to debate this any longer - YAWWWNNNNNNN!

So, here's my last contribution - hope it helps: Test the damn CPS!

(Note: This info came from a source indicating it was for '87 to '98 model years. I don't know if the distributor-less ignition on Todd's '00 rig would cause this info to be any different)

The Crankshaft Position Sensor, or CKP sensor provides the PCM with information about engine speed and crankshaft position. It is located near the bellhousing.

The CKP sensor contains a Hall effect device which sends either a 0.0 volt or a 5.0 volt signal to the PCM depending on the position of the distributor shaft.

The PCM uses the CKP sensor signal to determine fuel injection event time among other things. The engine will not run without the CKP sensor signal.

1.Backprobe with a high impedance ohmmeter between the CKP sensor connector middle terminal and battery ground.

2.Verify that the resistance is less than 5 ohms. If the resistance is not as specified, repair or replace the wiring as necessary and continue the test.

3.With the ignition ON and the engine OFF, backprobe with a high impedance voltmeter between the sensor connector middle terminal and either of the end terminals.

4.Verify that a 5 volt or greater signal is present at one of the two terminals. If not as specified, repair or replace the wiring as necessary and continue the test.

5.With the ignition ON and the engine OFF, backprobe with a high impedance voltmeter between the sensor connector middle terminal and the end terminal that did not have the 5 volt or greater signal.

6.Crank the engine and verify that the voltage reading alternates between 0.0 and 5.0 volts or verify that the voltage reading is 2.5 volts (averaging voltmeters only).

7.If the voltage readings are not as specified, the sensor may be faulty.

 

[ColoradoRaptor]

Try reading EVERY word before jumping to conclusions ya :looser:. Sounded like he had a NO START issue at the time, not something that would run, then not run. I was explaining that with a NO START situation, it certainly could be the CPS and to check spark to confirm.

In my later post, I read his post describing the symptoms more clearly (said it runs but dies unpredictably) and since that wasn't a NO START condition, I posted that it couldn't be the CPS - because the CPS won't allow the engine to start when it goes bad.

XJTodd: Could you try posting slower so 'Raptor can keep up? Thx!

:twak:

Sounds like you had to do some keeping up yourself:laugh3::moon::twak:

 

[XJTodd]

*SIGH* --

Well, I thought it would be great in a way if it died again on me, but almost doubted it would actually happen.

This morning it happened...on the way to the PnR this morning the Speedo was all %#$%@#$ up, swinging as much as 20mph.....20-40-20-40 and so on. Nothing felt or sounded like anything was running poorly. As I pulled into the PnR parking lot, it died.

Couldn't have been a worse time as I was already running late for work.

I DID notice that there was something going on electrically for sure. Lights REALLY dimmed the 3-4 times it took to try to get it started back up. I'm thinking this is definitely either a short somewhere or loose connection (or battery of course).

I guess I'm getting closer to something here. That was a really telling morning. Hopefully it will start when I get back to the PnR so I can get home. Now I just have to fit some troubleshooting in.


BTW: Yella, where did you get that CPS info? I never found anything that descriptive anywhere.

 

[FlexdXJ]

hmm..... by reading through this i think i have a bad TPS , it threw a code too, P0320 if i recall correctly, twice but never shifted funny or anything i may have 2 separate problems though

 

[ColoradoRaptor]

*SIGH* --

Well, I thought it would be great in a way if it died again on me, but almost doubted it would actually happen.

This morning it happened...on the way to the PnR this morning the Speedo was all %#$%@#$ up, swinging as much as 20mph.....20-40-20-40 and so on. Nothing felt or sounded like anything was running poorly. As I pulled into the PnR parking lot, it died.

Couldn't have been a worse time as I was already running late for work.

I DID notice that there was something going on electrically for sure. Lights REALLY dimmed the 3-4 times it took to try to get it started back up. I'm thinking this is definitely either a short somewhere or loose connection (or battery of course).

I guess I'm getting closer to something here. That was a really telling morning. Hopefully it will start when I get back to the PnR so I can get home. Now I just have to fit some troubleshooting in.


BTW: Yella, where did you get that CPS info? I never found anything that descriptive anywhere.

Check all your grounds!!

 

[Glacialbass]

Did you ever determine the cause of your problems?