l am working on a 1996 Jaguar XJS with a 4.0L engine, came in with High Idle (around 2000RPM) I checked the idle air control and one circuit was open. I replaced the Idle Control Motor and the idle is still around 2000. I pulled the throttle body, cleaned it and checked the gap on butterfly, it appeared ok. but the idle control motor was open, ( had a big gap between pintle and seat.) So I plugged the hole where the Idler control motor goes with my finger and had someone crank the car. It would idle around 700 and with the idle control motor plugged up, it advanced the pintle out. I reinstalled the idle control motor and then the car ran about 750 rpm and idle control motor was controlling the idle. The next day I cranked the car and idle is back to 2000 RPM. Can anyone advise me as to what I need to do to correct this Idler issue on this XJS. Thank You in advance for any help you can give.
Thanks
Rondy Bryan
Bryans Auto & Equipment Repair

 

Welcome to the forums Baer,

I've moved your question from General Tech Help to XJS forum. Members here with the same model will be able to help.

Please read the guidance for new members ( https://www.jaguarforums.com/forum/n...ned-up-241802/ ) which answers many of the most frequent questions about getting started.

Graham

 

Most of the time a simple TPS Reset is all that is needed...the trouble is finding a machine that can perform that task.

Your Jaguar dealer should be able to still do it and charge you for one hour's worth of labor....or you could try any shop that specializes in Jaguars.

You would need a PDU/VCM/WDS or Mongoose. They make aftermarket clones for about what a dealer will charge you, but they tend to only last a few times before something goes wrong.

It sounds like your idle air control valve was bad, but you replaced it without fixing anything, so I assume it's gonna be the TPS reset.