Originally posted this in the wrong part of Jaguarforums, my apologies for a duplicate entry.

What should I do next? Thought I would get a nice purring cat, and I got hissed at. Here are the details of what I've done:

My 2003 XJ8 was hesitating on pressing the accelerator pedal and seemed sluggish. After reading the forums it appeared likely that the throttle body was dirty and that the MAFS should be cleaned. Indeed after removing the air intake duct I found a TB with a good amount of soot/carbon build up.

Using TB cleaner and a shop rag I cleaned the TB as best I could. I worked around the perimeter of the intake rubbing off the build up, and also cleaned the edges of the butterfly valve. There was some carbon on the ends of the shaft that the butterfly rotates on so I sprayed them directly to clean them off (perhaps a tad overzealous and getting a couple ounces of TB cleaner down the pipe).

Cleaned the MAFS with CRC electronic parts cleaner so no residue would remain.

Also cleaned the air ducting and got oil residue and dirt out of it so it wouldn't be sucked back into the TB.

When I restarted the vehicle I was greeted with a rough idle and the red dash light illuminated.

I suspect that some of the residual TB cleaner didn't agree with the Jag's sensors.

I've disconnected the battery and I'm leaving the car for a few hours to allow evaporation of any residue and for the ECU and sensors to reset.

Help please....

 

a hard reset should sort it out. It has to recaliberate the throttle after the cleanse.

On next startup the revs should rise, don't be alarmed and go to shut it off, it'll fall back down to almost stall as the maf/throttle sort out a fresh map with the clean sensors, let it idle for 10 minutes so it can store the new airflow metering and fuel trims.

 

Thank you Sean.

I allowed the car to sit with battery disconnected for about 30 minutes (long enough to grab coffee and a bite to eat). Then started it up and let it idle for about 20 minutes. Kept freaking out about the red light because I'd open the door and look at the dash to see the red light was back on. I looked through the driver window and saw that it was off. Opened the door and guess what, back on. Then I had an AH HA moment, that same little light was indicating the drivers door was open. And I'm not even blonde.

LOL

I think it is working now.

 

Chris, welcome to the forums, glad to see your problem resolved so easily. If you have not visited the new member yet, please do so when you have time and introduce yourself.

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