New member with a 1996 XJ6 4.0L that I purchased a couple years ago because I could. I have already seen some very interesting information and have a ton of questions. I live in northern Minnesota and putting the car away for the winter I went to move it from the alley, the battery was dead so I charged it, opened the door my theft alarms started to go crazy, I pressed the unlock on the key fob hoping it would stop the alarm and it didn't, I quickly put the keys in the ignition and started the engine and the alarm stopped. I then put it in gear and I was not able to rev the engine whatsoever no matter what gear I had it in and I couldn't roll the window down. I shut the engine off and tried to start it again but it wouldn't start I bought a new battery but once again it will only move by idling in gear, and when you step on the gas pedal the engine remains idling. Is there something in the functions of the immobilizer that renders the gas pedal useless? Am I looking for a fuse? If so, which of the fuse boxes contains the fuse? I feel helpless.

Just idling in Minnesota

 

Throttle cable is probably disconnected. These cars in US spec basically don’t have an immobilizer

 

Hi D Nyquist,

Welcome to the Jaguar Forums! It's great to have you with us.

Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

And please report back after you've checked to see if the throttle cable is disconnected or broken.

Cheers,

Don

 

it's definately disconnected. I'm missing a link and I don't know what it's called. Someone stole a linkage part. I've have pictures of of what or where I'm missing the part and I found an engine picture that has the piece on. I've taken them to an NAPA (only part store open close by) and they were baffled. If I knew what it was called I might be able to find one.

 

Unfortunately the item missing is for the cruise/speed control. It missing would not prevent the throttle from opening. However if you can have some one press on the accelerator pedal see if the cable attached to the cam underneath that top cam moves

 

The part number for the kink you're missing is NBB3119AA but it's is discontinued from Jaguar. Shouldn't be a problem getting a used one, though.

That said, replacing that link isn't gonna solve your problem, as mentioned above.

When you press the throttle pedal does it feel like it's actually connected to anything?

Also, does your car have traction control?

Cheers
DD

 

thanks for the info about the part.
Yes it does feel like there's something connected but I'll need to get someone to see it work or not.
Not sure about traction control, if it came standard I've got it.

 

thanks for the info about my missing part. I must look elsewhere for my answer or fix that I'm in search of.

 

Oh, you are in the right place but I do urge you to add some information to your profile and signature line so as to allow the rest of us to better help you with correct particular information and put you in touch with vendors and fellow enthusiasts that may be in your area.

 

The reason I ask is because, if you DO have traction control, your throttle cable goes from the pedal to the traction control unit and then from the traction control unit to the engine. It's just another place to look for the problem.

Cheers
DD

 

I'm not able to determine if I have traction control, however, I can say with certainty that the throttle cable is attached and moves with the gas pedal. Since the cable is attached and functioning normally do I need to investigate further about if I have traction control or not?

Just Idling

 

If you have trac control there will be a TRAC OFF button next to the RES and ODO. Throttle body could be massively clogged to the point the the butterfly stays closed? Open it up and give it a clean.

 

Well is there another possibility possibly electrical? Throttle body is clean I do have TRAC FAIL light on dash before I start the vehicle but that's with every other light on the dash. They all turn off about 3 seconds after they turn on.

 

that’s just the bulb check

if you don’t have a trac off button you don’t have traction control

 

The traction control unit looks like this:

https://parts.jaguarlandroverclassic.../brand/jaguar/

...and will be on the RH side of the engine bay, near the firewall

Cheers
DD

 

There is a funny thing about that TRAC button, turns out the circuit board assembly is the same whether you have TRAC or not. The only difference is on the non TRAC switch panel is the switch cover is replaced with a blank cover that has a tab on the bottom to stop it from being depressed. A simple matter of removing the circuit board, pop off the switch cover and install the other. So it is possible a non TRAC switch circuit board can be installed in a traction control system and the system will work just fine. The only difference being is that you will not be able to disable the TRAC system unless the correct switch cover button is in place or you trim off the blocking tab on the switch cover.

 

And that as it turns out is the only sure way to determine if you have traction control installed or not. The switch panel circuit board is the same for both system, only the switch cover is different.

 

I have traction control visually verified under the hood. The linkage from gas pedal to throttle body is functioning properly without any difficulty, and the throttle body has been cleaned. When I start the engine cold it idles up (very briefly) and then returns to normal idling and I am still only able to idle.

Getting frustrated.

 

It blips up at startup because of the idle air bypass. If butterfly is moving revs should go up.

 

As you may have gathered, there is a large body of accumulated experience / pain / grief surrounding the traction control and throttle body on this forum!
The good news is that you have the normally aspirated engine, which starts and idles. Those are the really hard bits!!

The fact that it wont respond to throttle pedal inputs suggests a mechanical fault somewhere in the linkage. The guys are interested in the traction control as the control unit aka "throttle cable relaxer" is a physical element in the linkage between the drivers foot and the actual throttle body. There are two cables, one from your foot to the traction control, and one from the traction control to the throttle. The traction control unit has the ability to disconnect and reconnect the two cables as signalled by the ABS system in response to wheelspin. It would seem possible that either the cable from the traction control to the throttle body has broken, or the traction control unit has failed, resulting in a loss of connection between the two cables. Asfar as I can tell, the traction control unit tends to "fail safe" ie, the cables remain connected when it is powered down, so the latter possibility would seem remote.
You will see several posts about throttle cable adjustment, and it could be that your cables are simply out of adjustment, but given the car seems to have failed suddenly, I am inclined to discount this for now. As you have the normally aspirated car, all of the relevant parts should be in plain view, so you should be able to troubleshoot fairly easily. The fact that she starts and idles would suggest that there is a simple explanation. Famous last words.......