I got a clean 2000 Jaguar XJR, US version 82K miles that I seldom use. Lately I did not used it for 3 months and when I started it, it went okay but when it gets warm and a few miles, I got Check Engine Light and Restricted Performance message and when idle or slow speed it jerks when I press quickly the pedal however it can accelerate eventually in due time.

So I initially put a can of Injector cleaner, it seems to improve the roughness of the engine but the Restricted Performance is still there,

Then decided to clean the air intake from the K&N Air Filter, MAFS and Throttle Body. When I fired it up, the Restricted Performance message is gone, but obviously the check engine light is still there. It was idling beautifully. So I cruised around the neighborhood with no messages or warning and after a few minutes go on the freeway, traveled around 10 miles or so, still good, slow down at the next ramp exit to go back then the Check Engine Light Starts Flashing and I was still cruishing when the Restricted Performance message appeared and the Check Engine Light Stays ON. So I have to home to safely park the car.

In the mean time I ordered a set Ignition Coil Packs (8), not sure if this is the culprit.

Please HELP, I love my Jag, although it is old, it still got a lot of onlookers and praises even from people I do not know.

 

rreventar, you need to buy an OBDII reader and check for what codes are being created, otherwise you are groping in the dark and throwing money away on items that are probably not necessary.

 

Take it to a local auto parts store like Autozone or any other that reads codes for free. Throwing parts at a Jaguar without knowing what is wrong is an expensive way of resolving a problem.
Get the codes read and post them. We can give a better diagnosis then.

 

You do the old disconnect-reconnect battery trick?

 

My car suffered a dual fuel pump failure while sitting in the garage for an extended period. I replaced both pumps, but forgot to replace one of the fuses that I had pulled during the trouble shooting process. That triggered the restricted performance light and symptoms similar to what you describe. I guess you could be operating on one pump....

 

Thanks Carnival Kid, I did took your suggestion and ordered a scanner at Amazon, you are right my car is getting old and need to have my own diagnostic tool.

 

Thanks guys, I really appreciate your input and diagnostics. I read as well last night on a different thread about a K&N filter that is oiled coated which kind of add inpurities to the MAFS while it is running. I had a K&N filter, it has full of grime and dirty so I went to Autozone and bought a conditioner where you spray clean the filter and wash it off, let it dry then apply another spray can which is oil based and let it dry. I was thinking I might have overdone it in the process (too much oil) because when I first clean the whole air intake, the car runs like a breeze for 10 miles and when I slowed down, the dreaded Restricted Performance appeared again.

This afternoon, l took out the MAFS again and spray clean it and replace the K&N filter with my old standard paper filter. Upon starting, in 30 seconds the Restricted Performance disappeared. I drove around my subdivision a few times and head back. I am not sure whether It solve the problem but I need to stop because I am schedule to do an Emission Test tomorrow and my OBD2 from amazon will arrive tonight, that Check Engine Light still needs to be reset. Wish me luck ! I will let you know it this quick fix holds thru. Thanks again, I love this forum, I can learn a lot.

 

Just a warning, I'm pretty sure if you reset your error codes the car will need to be driven a set amount of miles to allow the computer to "reset", and if you try to do a emissions test before this occurs they will probably not be able to test the car. Others are probably more knowledgeable about this,but I think this is the case.

 

Yes, be very careful about deleting faults. When I did my fuel pump replacement The check engine light went out on its own. So then I checked the overall system "readiness for emissions testing" function on the OBDII. All systems were "green". Cool...so I then decide to delete the individual malfunction codes that had accumulated in the pending file (resolved items on temporary hold until the system decides to clear them on its own). My OBD cautioned against this. I'm a dumb *** and push the fault delete button. This flipped every computer in the system to red (not ready for emissions test). Supposedly, the fastest way to get them back to ready status is to perform the "drive profile". Most systems came back after two runs through the profile. A few took up to six runs (well over an hour of driving). I had given up on the CAT system when it popped to green as I pulled in the driveway. Once I got all systems green I went straight to the emissions testing station. It passed. (Texas...and some other states... allows one "red", by the way).

 

Hello fellow jags, I took your advice to go to Autozone for OBD2 scanning and got a code P0300 with multiple misfiring on some coils and spark plugs. I bought a set of coil packs (8) and NGK Iridium IX spark (8) 5464. Asked a friend to help installed it, after a few hours fired the engine and the Restricted Performance reset in a few seconds running. Took it for test drive for 20 miles, Check Engine Light was still on.

Drop by Autozone the following morning, said no more problem on misfiring but I need to drive at least 50 miles to reset it, drove it another 30 then proceed to the Emission Test. Did not pass because there was not enough data for their scanner to read the Catalyst, O2 Sensor and the EGR, the technician suggested I need more mileage in city driving (stop and go) to test the emission. So I drove around for 60 miles wasting gasoline on city streets (stop and go) and on the highway. Went back to Emission before they closed and finally passed the EMISSION TEST. I went home and immediately renew my registration online.

Next on the lists is to put fuel injector cleaner. BG 44K seems popular on this forum so I ordered it on Amazon, surprisingly they are not available at Autozone, O'Reilly or Napa.

My car is almost 20 years old, so this escapade is a wake up call for me since I seldom drive it but I want to keep it forever. MANNY THANKS TO THOSE WHOSE RESPONDED AND GIVEN ADVANCE.