Idle too high - 1998 XK8 base convertible -Florida

Problem: intermittent idle not coming down past 1,500 rpm when taking foot off gas rolling to stop. Once almost stopped will drop to normal level again.

Not all the time. But once it starts behaves like that till I park it. Next time may have no problem all day.

1st thought it was dirty TB , or connectors. Maybe 02 sensor or vac hose leak? Have not done this maintenance yet.

Is is possible to " reset" the idle with key in # 1 position at start up , 2 pumps to floor
Wait a minute. Then start car. Let idle for 5-10 minutes to set. Or could this lead to more issues
I read this is a fix when changing out TB , disconnecting battery.

I feel like pain- in- the-butt asking all these questions. But I am new to Jags.
Thanks
Mike

 

You could first check your fuel trims via a scanner, if she's reading rich, the car's gonna through more air into it and you'll get a higher RPM as a result. Your throttle cable could also be adjusted too tightly, but since is dropping after you come to a complete stop, that probably isn't it. More than likely your TB has a buildup of carbon deposits along the edges of the butterfly, and she's getting stuck returning to a fully closed position. Do the maintenance that you've listed above, then you;ll know for sure.

 

Thank you I will do that. Love the pic of your O3! Mike

 

I had a high RPM problem and posted a resoltion at the original thread here:
https://www.jaguarforums.com/forum/x...igh-rpm-84948/
Might just help...