This is a little strange to me. The restricted performance comes on "every other time" i start the car and stays on until i cut the car OFF. If i re-start the engine right after cutting it off, the restricted performance goes away. The car runs normally (perky Jag!).

What do you all think this may be? While at the Jag dealer, a little time ago, even thy did not diagnose it properly (they said they may have to smoke it to try and chase down a leak. A different Jag Mechie says it may just be the purge valve. How can that be, if you can just turn it off and on again and it runs OK?

Any thoughts fellow Jags?

 

Any codes?

Check battery voltage after overnight without starting engine, should be 12.6 or more.

 

However, the battery is new (last 3 months). This problem predates that.

 

Maybe time to invest in a cheap OBD reader and plug it in, or go to Autozone and have them plug it in while the restricted mode is active...the port is under the steering wheel next to the trans tunnel. I use a memoscan OBD reader for quick diagnosis.

Basically the code will point to the fault and then we can suggest a fix.

Otherwise is guesswork.

 

The same thing happened to me... After two years of fixing different things, the fuel pump failed.. And after I replaced it, I don't get the yellow light anymore.

 

Believe it or not, mine went away after replacing ground straps.

I think the proper procedure for diagnosing restricted performance issues is look at everything that is attached to, in or around the car. At least from what I have seen and read....