Can someone help me....... ive taken a look into my throttle body and with the gas pedal to the floor my butterfly will only open 65 to 70 percent,,, is this right or should it open 100 percent. Im confused , wondering if thiers a vacum that takes over at some point......... Would u guys know what the answer is and help me get some peace of mind.................2002 xk8 convertible 4.0 engine

 

Just do a search for Throttle body cable adjustment and you will find the answer.
RJ_____________
97 XK8 Conv. 85 K mi

 

Ive havent found one that will tell me if thier butterfly will open all the way when they press the gas pedal to the floor, they mostly speak about setting the cable but not answer my question......... Does the butterfly open 100% when the gas pedal is all the way to the floor........ this is really eating at me........ Help is needed. MIne will only open about 65% so thats what i need to know......... I seen other units open all the way but they were not 2002 xk8s ,,,,, some were american cars so again im left with that question. When i turn the throttle cable holder all the way , the butterfly will not open but 65 % and its even less with just the gas pedal.. Is this normal or is something wrong........ any help would be great. But if i take my hand and grab the butterfly i can turn it to 100 % so now im really confused

 

It should open 100%. That means straight up and down, at 90 degrees from closed position. Most likely you just need to adjust your cable. Simple fix and you will see an instant improvement in throttle response.

I think there is a picture of the open throttle before and after adjustment on one of the older threads.

 

Found the thread. There is a before and after picture, plus analysis. See post #15. There is a youtube video by the Reverend to show you how on the later models. Works about the same on the earlier MYs.

Be sure to read the section on resetting your memory to read the new throttle travel. Otherwise, it will take many miles before it learns how to use the fix.

 

Not sure why the link was left off last post. Here it is:
https://www.jaguarforums.com/forum/x...estored-38663/

 

This'll be the link https://www.jaguarforums.com/forum/x...estored-38663/

 

i have the ae program , i assume that the car is not on when this test is run. Also i have no idea what the wot means or is. so thanks ahead for the info. Remeber i tried to open the butterfly from the throttle cable holder and it would not open 100 % so ideas or needed

 

ran the test and the pedal position sensor can only get 55% so what is it a bad sensor or something else. No matter how much i adjust the cable its still 55% so any ideas

 

WOT = Wide Open Throttle

Just to be sure, as you push the pedal all the way to the floor:

1. the pedal contacts the kick down button underneath without any interference
2. you can then push the pedal further making the kickdown switch "click"

Just looking for interference points.

Can you reach the cable where it's hooked to the pedal bellcrank and pull on it to open the throttle to 100%?

How many miles on the car?

 

The Pedal Linkage can only open the Throttle partially.

It only opens the Throttle mechanically when the Throttle Motor Fails or with the key off.

Only the Throttle Motor can open the Throttle 100%.

 

Thanks for all the help. Ive changed just about everything on my xk8 so i said here goes some more money..... Throttle cable ajusted to take all slack out, with the key in the on position the butterfly will open all the way, with the key off it will only open half. So you are right the little motor will take it the rest of the way. Thanks again guys for all the advise

 

Do a train anyway. Key on, slowly depress throttle to kickdown, hold 5 secs, repeat.
It does make a difference

 

Steve,

I may have missed out on some of the detail in the throttle 'training' debate. Does this definitely apply to both 4.0 litre and 4.2 litre or only to 4.2 litre?

Graham

 

Aaarghh - missed the magic 4.0
(please put your car details in your signature Nag Nag)
You're quite right, I'll get back in my box.