will not go into kickdown acceleration and brings up no failsafe or limp codes, has not been driven in 4 years only 35,000 miles ?????

 

Welcome to the forum cbrit,

I've moved your question from Jaguar Forums Feedback & Suggestion Centre to X308 forum. This is the place to post technical questions about your model.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

 

There are 2 main reasons that the kickdown is not working. First the throttle is seeing and communicating to the ECU that you are at Wide Open Throttle (WOT) and second is that your kickdown switch is defective. Since the ECU is seeing something for kickdown and can't match values to determine an action your switch is most likely good.
That leaves you are not at WOT, the common cause for that is stretch in the throttle cable. If you remove the snorkle intake and check the cable it probably has too much slack to go to WOT. You can clip the tie wrap that holds the cable to the throttle body and lift the square plastic holder out and adjust the cable to remove the slack. If memory serves me from the last time I did it you rotate it towards the throttle. Once the slack is out reinsert and apply a new tie wrap.

 

thanks very much I will check that but at idle it revs freely, is there a fuel filter, thanks again

 

The fuel filter is in front of the left rear wheel, but that is probably not the problem. As Vern suggested, the throttle is not opening all the way, an easy check. It's also possible that the kickdown switch needs adjusting. It's under the throttle pedal and can be turned to adjust. But check that the butterfly is opening all the way first.

The engine will rev freely in neutral, but should not go over about 3000 rpm by design.

 

AFAIK, there is NO kickdown sitch for early models.
My 2000 XJ8L is without one as well!
Cheers, John

 

I am not positive but i believe this is the part number for the kickdown switch LNA6570AD . They were used on the XK8 and XJ8 thru 1999. Then discontinued with the cahnge in throttle bodies.

 

 

Sometimes the "switch" is not really one but feels like one (or is not connected). The PCM figures out kickdown/WOT.

 

I had no part throttle kick down as well. It was slack in the throttle cable. Rotating the throttle cable bracket relative to the cable fixed it. I rotated the bracket clockwise to shorten the cable 2 turns.