Hello everybody i got a xkr.. In the performance restriction light come on.. on and off at time.. when it come on the vehicle stalled.. and dont wanna go oover 40 mile per hour.. and i will cruise for about ten seconds then it will go off and back to normal...

 

Does the light go out after the car cools down and sits for awhile? Or by the next morning does it run fine?

I had a res perf on my 99 coupe recently and the cause was a bad coil pack. But the car never stalled out or any thing . When it cooled down the res perf light would not come on until the car got hot. Coil packs are about $120.00ea Car Quest-$175.00 Jaguar . I'll pull my invoice from the repair and post the codes I got.

 

na the light come on when d car is park.. i dont have no miss fire

 

Mine never had a misfire just a light, but the idle was a little irradic while waiting for the traffic signal to change.
I just reread your post about not wanting to go over 40mph. I assume your talking about the car.

I believe that is limp mode speed maybe its 50 for limp mode speed. If you look up limp mode or restricted performance in your owners manual if may lead to the tranny. Forget that, that is a fail safe light. Ah hell i'm at a loss.

 

I had the exact thing happen to my 1999 xk8, and found it to be a very easy fix (at least in my case).

There is a vacuum hose on the drivers side intake manifold on the engine (that 'tucks' underneath the plastic cover) that has a reducer on it. Mine was fatigued and allowed air to seep through, thus restricting the proper amount of vacuum to run smoothly.

I could even hear the air coming in while the engine was running (especially when I 'jiggled' the fitting around a bit.

I had no idea that a vacuum leak could cause such havoc (jittery idle and 30 MPH max).

You may have to reset the 'check engine' light once it's fixed.

I hope your fix was as easy as mine.

 

i took a look at the air intake system.. i found some small cracking in the system.. will that make d light come on

 

I wouldn't think that would make the light come on but I can tell you how to repair the snorkel if you like. Or you can buy a new snorkel from jagtech ohio for about 70.00. https://www.jaguarforums.com/forum/s...ad.php?t=23576 This shows how gus repaired his snorkel and how I repaired my snorkel. You could also clean the MAF sensor. you do not have to take the whole air box out. Just carefully remove the wire harness then take out the two phillips screws. Spray the probe with MAF cleaner. allow to dry and install in reverse order. you can easily tell if the sensor is dirty because it will have an amber dingy color on the metal, and generally just look dirty; just above the bulb on the end.