Firstly, My name is Rick and I recently purchased a 2000 XJR.

Secondly, like many others I too am intermittently experiencing the Restricted Performance issue.

I took the car to my local Advanced Auto and it threw a number of codes:

P1111 - Which I understand to be an all systems nominal code

Lean Bank 1 & 2 and O2 sensor codes.

I was told the problem may be with the MAF, the accordian tubing, or a random vacuum leak.

There doesn't seem to be any predictability to when it will occur other than that the car seems to do it more often at red lights and stops once the car is moving along at highway speeds.

This leads me to think it's a vacuum leak, but I do not know enough about the vehicle yet to know where to truly begin looking.

Any help is appreciated.

-Rick

 

Welcome!

Is the check engine light "on" ?

You should list the codes so we have a better idea. Wondering what the O2 codes are?

I would invest in an inexpensive code reader -- you can get them on Amazon for as little as $35.00. It will save you from running to the Autozone and allow you to clear the codes and see when and what codes pop up.

Vacuum leaks can be a pain to locate but obviously check the intake for any cracks. What you do not want to do is to start to remove a bunch of parts without having any idea of the problem.

Same goes for ......say removing the MAF and cleaning it -- Who told you you may have a MAF problem?

 

Welcome Rick. This forum is INCREDIBLE. People here go out of their way to help. I'm a new '01 VDP owner myself and have learned so much from my new Jag friends here. It's like you adopt a new family!

I too have a couple codes I'm now dealing with. One is LEAN ON BANK 1 and for me it looks like an easy fix as there are several places (breather hoses) that are not fully/well connected. I've ordered the new hoses (full and part load breather hoses) and have a mechanic coming on Tuesday to replace them along with some other work. From what I've learned so far is that the LEAN issue means that there is some connection (or hose!) that's not sealed which is allowing outside air to enter the system thus causing the lean condition.

My other code is indicates CAM POSITION ERROR SENSOR. That will need some diagnostic time and I'll put my mechanic on it next and let everyone know what he comes up with.

I get the RESTRICTED PERFORMANCE message too. Until I replace the breathers I won't know if THAT is the issue causing the RP warning.

Keep reading this forum... you will get to the bottom of your issues. My goal is to make this baby purr again. The previous owner was apparently a real $%@# when it came to taking care of his car. This cat needs love. It gives me so much pleasure just looking at her when I approach in a parking lot that I owe it to her. ;-)

SirJag

 

The previous owner said the MAF was most likely the issue.When I get off work today I'll go get the codes read again. I was exhausted and in a hurry to post before I went to bed last night.

Yes the CEL is on though. It stays on all the time.

 

You are lucky to have a CEL. I've been chasing a stumble in my car for quite a while now without a CEL or any codes.

I was recently informed that the oil dipstick also is a source of a potential vacuum leak. Check the o-ring on that too.

Take a look at my thread titled "Hesitation, stumble, miss..." I'm trying to capture all of the possible causes there. I recall seeing that XJR's have a fuel line that can kink due to age and noted it there. https://www.jaguarforums.com/forum/j...ad-2036/page2/

Regards, Ken

 

The first thing you want to do is look at the codes and work from that point.

With my RP incident the CEL was not illuminated -- you may have an O2 problem that is causing the CEL and another issue causing the RP.


You don't want to dive into a problem based on what someone else said without knowing why. MAF sensors can and do cause problems -- but you often get a code that is directly associated with the MAF sensor.

How much did the previous owner play around with this problem? Did he replace the MAF at some point? If yes was it an OEM part?

 

On the code reader, I suggest spending $82.00 and getting the Equus 3040. I got a brand new one on fleabay and it got to my house in 2 days. I followed Glendoramike's advice on this one and am glad I did.

The nice thing is it has "Live Data" which allows you to see actual sensor readings. You will need this info if you can't find a specific hard fault.

The only advise I have is stick with doing a diagnosis. Changing parts will get costly. For example the MAF is $287.00 and is not returnable if it was not the problem. Also by learning the diagnosis you will have a better understanding of how efi works. This will definitely be needed knowledge as your car gets older.

Ken

 

The previous owner didn't do anything about the problem. He said the RP would only stay on for a minute or so and then stay off so he never bothered to fix it.

I'm going to get the codes reread when I get off work and look into buying my own reader.

I don't remember the codes off the top of my head, but I remember some of what they said when I had it done last night though.

P1111
Lean Bank 1
Lean Bank 2
O2 Sensor

 

Often the information you get from the auto stores is incorrect as to the code description for Jaguar.

Post them and some one will help you.

 

If you have a vacuum leak, chances are you will not be able to visually find the problem. Time to visit an indy mech with a smoke tester. Will save you time and money.

 

Are there any issues with running seafoam through the air intake with jaguars?

 

Welcome to the group. Where in Florida are you?

As far as being overwhelmed, try not to get that way. It's a myth that Jaguars are terribly complicated. It is true that certain areas are difficult to work on but that is about it. Most mechanics (from my personal experience) claim that they are too difficult to deal with. None of that is true if being lazy isn't a factor. Read up all you can and do as much on your own as you can and not only will you save a lot $ you will wonder why you thought you needed others to do certain things.

Again, welcome to the group. Lots of info here and there is nothing that can happen to your car that someone else hasn't already had to deal with. The point of that statement is to just let you know that you are not alone.

 

I'm stationed in the Pan Handle currently. About half an hour away from Pensacola.

Trying not to get too overwhelmed. It's not from frustration, but there is simply so much knowledge to try and absorb haha.

So I went back to Autozone and had the codes rerun

P1111
P0171
P0174
P0133
P0153

One thing I noticed is that one of the plastic things that sticks off the accordian was broken and kind of jurry rigged back in. I'm buying a new housing for it.

 

I decided to check and see if the MAF was dirty and bought some cleaner. I followed the instructions and when I inspected the MAF it looked like it had oil on the sensor and a small amount around the housing. I cleaned the MAF, waited for it to dry, and then reassembled the whole thing. I also checked my air filter while I was at it and it's clean too.

Going to get the codes reread once I fix the vacuum leak.