Hello everyone!
I have a 1996 XJ6 that has 98K miles.
It has been running really well and when I went to have it inspected I got a code of the Camshaft Position Sensor.
The car has taken me places but every now and then would turn off specially on a stoplight, I "bypassed" the problem by putting it on neutral where it reved up quite a bit but the car kept running.
I don't feel any sort of misfire, the engine feels quite stable.
We had a few extremely rainy days here in Dallas and I went to the store no more than 7 miles away and on the way back the car started stalling, power was extremely low and it was turning off, when I got to my street which is very low in traffic I accelerated and the car responded after a few seconds.
I checked the camshaft position sensor and the ring that's visible is turning fine and evenly, no spikes. It makes me wonder if it's something to do with the wiring or the actual sensor information sending performance.
There is also on the passenger's side, between the brake pump and the power steering fluid reservoir a couple of connectors from a wire harness that don't have anything to be plugged to. They look original, not cut or tampered with or adapted and even underneath the plastic storage bin that has some spare fuses, which is as far as those connectors will reach, the cables are quite short, there's nothing to plug them into.
Any suggestions on where to look further or how to test and solve this issue?
Thanks!!!

 

The 2 extra connectors go to the traction control actuator other then the ABS module not on all vehicles and the wire harness for the camshaft sensor go up and over the fuel rail . Look at the 2 ECU connectors on the far right side by the right foot behind the small panel .

 

Thanks!
I will do that!
Do you know a way to bench test the camshaft sensor?

 

It's a hall effect sensor and maybe there is something on Youtube . I had the #P0340 code also but went away after cleaning the connector so it may have been a hiccup or a mechanic induced trip some years ago . Something to keep in mind the Camshaft sensor is used in the starting sequence and then the Crankshaft takes over . The Crankshaft sensor can partially fail and cause different problems without showing a code . Is the tachometer on zero before the engine gets there as it engine spins down ? The Crankshaft sensor also gives the command to keep the fuel pump running after the initial 3 - 5 second on / off priming sequence .

The Crankshaft sensor will read 1300 ohms and is a inductive sensor

See PDF below :

http://www.jagrepair.com/images/Trai...20-%202000.pdf..........Page 51

 

As you probably can imagine I already ran to the car! Everything looks normal. The tachometer works properly!
The ECU Connectors you told me, which are mostly yellow are slightly moist! That of course has to do something with it! On the first connector there is nothing connected to it and the next two are fine.
When it rains heavy all the windows get fogged while the car is parked so there's definitely a small leak somewhere.
I'm thinking a hair blow dryer and some patience can get that area dry without damage, it's definitively not an area that will dry by itself, not even on a hot Texas day!
What do you think?

 

Alcohol will absorb the water and wash it away , suggest turning ECU upside down to help it from going inside . Spray the car side connector as well and shake out . Lastly put a protective spray of oil in the connector . Are the seals on the wires as they exit the connector ?

The tach check is as it dies in the heat of battle if you remember to look at it

 

Thanks!
I will do that! I don't have alcohol handy but I'll get some tomorrow!
Have a great day!!

 

Hi ebrisec,

Just to elaborate on the excellent replies you've already received from Lady P, the Camshaft Position Sensor (CMP) is only referenced at startup so the Engine Control Module (ECM) can identify cylinder 1 top dead center on the compression stroke. This happens in less than one full revolution of the engine. From that moment on, the ECM ignores the CMP and instead references the Crankshaft Position Sensor (CKPS) to manage ignition timing. All that to say, the CMP is not the cause of your stalling.

One known cause of stalling when slowing to a stop or to make a turn is low transmission fluid, so that is the first thing I would check, and if you find it is low, identify the point of the leak.

The moisture on your ECM connector can definitely be a problem. Regarding protecting the connectors from water, it's important to remember that some of the sensor signals the ECM relies on may depend on variations as small as tenths of an ohm. If you spray WD40 or apply any other type of lubricant or grease onto the pins and sockets inside the connector, you risk adding electrical resistance that can affect the signals received by the ECM, leading to incorrect fueling, timing, rough gearshifts, reduced fuel economy, increased emissions, etc.

My preference is to apply dielectric grease around the outside of the smaller half of the connector housing so that as the two halves are mated, the grease fills the space between them to help prevent water ingress, but leaves the electrical contacts clean and dry. Here's an example of a connector to which I have applied dielectric grease only on the outside of the housing of the smaller or inner half of the connector:


Another great product to keep on hand is zero-residue electrical contact cleaner. Most auto parts stores stock it (CRC is a popular brand - you want the Electrical Contact Cleaner and not the Electrical Parts Cleaner).

The small packets of dielectric grease sold as "bulb grease" won't contain enough grease to do the job on the ECM connectors, so I would recommend you buy a full tube. (CRC sells it in an aerosol can with a dispenser nozzle but the can always seems to run out of propellant before all the grease is dispensed. Permatex and others sell it in a small toothpaste-style tube and that is my preference).

Cheers,

Don

 

Thanks Don! I ordered a few hours back the CRC electrical part cleaner, it won't hurt to have it on my garage and thanks to your advice I just ordered the zero residue contact cleaner which will be the one I use!
Cheers!!

 

I am a big fan of Deoxit for cleaning terminals.

 

I've used Deoxit too, primarily on audio connectors. But it's fairly expensive, at around $15 for a 5 oz. can, compared to around $8 for an 11 oz. can of CRC. And after comparing the Deoxit D-Series material safety data sheet with the one for the CRC, I suspect they are very similar chemically. Roughly 90% of Deoxit is a combination of naptha (paint thinner) and aerosol propellant. Roughly 90% of CRC Contact Cleaner is a combination of 2-methylpentane, naptha, and aerosol propellant. Caig Labs doesn't specify the 5% of its contents that are claimed to be "active," labelling them a "trade secret," but CRC lists all of its ingredients (ten in all).

If I recall correctly, some of the Deoxit products leave a thin residue that contains graphite. Since graphite is many times less conductive than the copper, gold or aluminum used for most automotive connector terminals, I personally avoid those products. Zero-residue seems best.

Here are the MSDSs if anyone is interested:

Deoxit D-Series 5% Spray MSDS

CRC QD Contact Cleaner MSDS

Cheers,

Don

 

I've used both. While CRC may certainly be a suitable substitute, Deoxit seems like it works much more aggressively. It appears to attack oxidized metal like hydrogen peroxide on a wound. I find it much easier to clean up when the metal is heavily oxidized (used it on window switches), making me feel more confident that it works that much better when the metal isn't so bad off.

I've never heard of any graphite residue being left behind from this stuff. Couldn't even find anything on the interwebs that mention that. It's only purpose is to clean electrical contacts, and it has a strong following where excellence in contact is needed, particularly the DIY circuit building/robotic communities as well as the audiophile/music communities.

 

I first heard about the Caig Laboratories products in the audiophile and professional recording communities (Stereophile and Absolute Sound reviewers were early fans). It seems like Deoxit was introduced sometime in the '90s, if I recall correctly, and prior to that Caig was marketing products from Cramolin. Back then, some of us commented on the contents of these so-called "contact enhancers," which contained graphite, which is a few orders of magnitude less conductive than the metals commonly used for electrical contacts (copper, silver, aluminum, brass, nickel, gold, tungsten, platinum, cadmium, steel, etc.). This led us to question how it could possibly "enhance" any electrical connection. And, if its use was audible as some claimed, was the effect actually non-linear and further removed from faithful reproduction of the original source?

From a quick search it appears that Caig Labs has revised its material safety data sheets to list all "active" ingredients as "trade secrets," so it's impossible to tell what's really in it aside from the main solvent and propellant. The one thing I did notice is that their Contact Cleaner & Lubricant contains 10% - %30 mineral oil, so that's certainly a product I would avoid, since mineral oil is an electrical insulator.

Cheers,

Don

 

 

Your idle is too high.

It should be in the high 500s-low 600s in drive and low 700s in Park or neutral.

You probably need your Throttle Potentiometer Sensor reset. Anyone with Jaguar specific software can do that.

That is probably unrelated to your problem here. If you got a camshaft position sensor code thrown, I'd replace that part, however your symptom sounds more like the crankshaft position sensor going bad. Are you sure you didn't mix those two up, I know I do that all the time.

 

Thanks Vee!
I also think is the Crankshaft Position Sensor. What are the symptoms or "stages" of this going bad? I unplugged it and the car died and wouldn't start as expected, but when I plugged it back it started right away with absolutely no effort! Autozone ships it for free overnight for 130$ new, so I think I'll do that.
Will the throttle potentiometer adjust itself once this is changed?
Thanks!!

 

Thanks Vee!
I also think is the Crankshaft Position Sensor. What are the symptoms or "stages" of this going bad? I unplugged it and the car died and wouldn't start as expected, but when I plugged it back it started right away with absolutely no effort! Autozone ships it for free overnight for 130$ new, so I think I'll do that.
Will the throttle potentiometer adjust itself once this is changed?
Thanks!!

 

Hi ebrisec,

The engine can't run without the Crank Position Sensor (CKPS) because it provides the principal timing signal for the Engine Control Module (ECM). Failure modes for the CKPS vary from intermittent to sudden no-start.

Regarding your high idle, you could have a problem with the Idle Air Control Valve (IACV), which is part of the throttle body. An electric stepper motor moves a plunger in and out to allow more or less air into the intake when the throttle butterfly valve is closed. The plunger and the port in which it fits tend to become fouled with black gunk, which can prevent the plunger from closing completely. Another possible problem is with the electrical connector to the stepper motor, so it would be work disconnecting, inspecting and cleaning it.

Cheers,

Don

 

You can clean the IAC valve but is hard to remove and the bolts break sometimes . With the middle wire on the TPS with the butterfly on the closed stop ( sometimes they get bound up with guck up or the throttle return spring is weak as there is TSB to put a stronger spring in ) you should read 0.60 + or = 0.02 volts . If it is not , record the value and with a lot of patients you can losen the mounting bolts under there to twist it . You may have to drill the holes out bigger on the TPS to get some adjustment like I did on mine to put it on 0.60 as it was on 0.63 . You can pick up this wire as it goes over the fuel rail and strip some of the insulation off .

It is important that you keep that initial reading as that may be where the last ECU " orientation " was done ( or not ) and my want to go back to that position depending on your results .

I you want to do the package deal remove the throttle body and do all 3 . Heat the IAC bolts to free up the loctite so not to break the bolts . They're a odd size like 5.5 mm . The TPS can be adjusted easier as the engine does not have to run the read it , just key on .

Something to keep in mind for the future , the crankshaft sensor will fail in some aspects and not fully and will not give you a code

 

Thanks Lady P and Don!
What are everybody's thoughts on cleaning the intake with SeaFoam or something similar?
It has done a great job on some older Mercedes' I've owned since sometimes a little piece of gunk that grew through the years gets just stuck in the right place and causes a headache!