Intermittent Acceleration on 2011 XF Prem Lux 2.2 Deisel

[Alan Matthews]

Just had a gearbox service at my local garage who are Jag specialists and deal with no other cars and are attached to the dealer I got the car from. I ensured they used all the correct parts and most specifically the correct Oil. I hoped this would cure an intermittent problem I had been having with acceleration, which is: on depressing the accelerator all that happened was the revs built up slowly, felt it was not changing gear, and slowly the speed built up. This happened even when I floored the accelerator. The next time I got in to drive the car I depressed the accelerator to get going then all of a sudden it shot off like a bat out of hell. This happens whether in Drive or Sport and there is no Kick Down either. Now unfortunately, it is happening all the time. Being a "fly by wire" system I have a feeling the the problem may be the the communication between the potentiometers at the accelerator and the throttle body which need to be reset. Of course when I mentioned this to the technician he basically just smiled and dismissed me.

Any thoughts or help would be greatly appreciated. 

[JOE-DOT-COM]

hi

try this.

How to manually reset Tps-re learn

Radio fan all off.

1. insert key Into ignition
2. forward 2 clicks so all dash lights are on
3. Put foot down on accelerator all the way down until you are pressing the kick down button and hold for 30 secs
4. While holding accelerator down switch ignition to off and remove foot from accelerator.
5. Wait 2 to 3 mins remove key then re insert start and drive.

 

[Alan Matthews]

4 hours ago, JOE-DOT-COM said:

hi

try this.

How to manually reset Tps-re learn

Radio fan all off.

1. insert key Into ignition
2. forward 2 clicks so all dash lights are on
3. Put foot down on accelerator all the way down until you are pressing the kick down button and hold for 30 secs
4. While holding accelerator down switch ignition to off and remove foot from accelerator.
5. Wait 2 to 3 mins remove key then re insert start and drive.

 

 

 

[Alan Matthews]

Hi Joe,

My car is Keyless Entry and automatic so this wont work but thanks for the reply anyway

 

Alan

[Bigvic]

It will

don’t put your foot on the brake when you press the start button

[Nicster]

Hi Alan

I had pretty much the same issue until eventually it had absolutely no power, had my mechanic look at it and turned out that the DPF was completely blocked.

Perhaps try pouring some DPF cleaner into the tank and go for a nice long drive at a constant highway speed (100Kph +) with some luck it will regen and clear.

[Alan Matthews]

Hi there,

Thanks for the response. My car does not lose power altogether it happens intermittently that as I set off the car will move, the revs build up but I am only just rolling. However, as I am rolling the speed increases and catches up. This can go on for a while and then all of a sudden it reverts to driving absolutely normally and can stay that way for many days and then it happens again. After having a discussion with my garage, (who is a Jag specialist) I told him that I thought it was a problem with the communication between the potentiometers at the accelerator and the throttle body, He initially was reluctant to accept this, but, after discussing it with the dealer I got the car from. he had another customer with the same problem some time ago and replacing the throttle body body solved it. So, the dealer has now arranged with the garage to replace the throttle body on my car (no charge) which is being done Wednesday and will hopefully resolve the problem. Will post again after I have driven for a while.

Cheers.

[Wrinkly]

3 hours ago, Alan Matthews said:

Hi there,

Thanks for the response. My car does not lose power altogether it happens intermittently that as I set off the car will move, the revs build up but I am only just rolling. However, as I am rolling the speed increases and catches up. This can go on for a while and then all of a sudden it reverts to driving absolutely normally and can stay that way for many days and then it happens again. After having a discussion with my garage, (who is a Jag specialist) I told him that I thought it was a problem with the communication between the potentiometers at the accelerator and the throttle body, He initially was reluctant to accept this, but, after discussing it with the dealer I got the car from. he had another customer with the same problem some time ago and replacing the throttle body body solved it. So, the dealer has now arranged with the garage to replace the throttle body on my car (no charge) which is being done Wednesday and will hopefully resolve the problem. Will post again after I have driven for a while.

Cheers.

Alan

Good dealer, not all of them are as upfront as this. Well done.

Best Wishes , John

[James 646]

On 5/22/2022 at 3:28 PM, Alan Matthews said:

Hi there,

Thanks for the response. My car does not lose power altogether it happens intermittently that as I set off the car will move, the revs build up but I am only just rolling. However, as I am rolling the speed increases and catches up. This can go on for a while and then all of a sudden it reverts to driving absolutely normally and can stay that way for many days and then it happens again. After having a discussion with my garage, (who is a Jag specialist) I told him that I thought it was a problem with the communication between the potentiometers at the accelerator and the throttle body, He initially was reluctant to accept this, but, after discussing it with the dealer I got the car from. he had another customer with the same problem some time ago and replacing the throttle body body solved it. So, the dealer has now arranged with the garage to replace the throttle body on my car (no charge) which is being done Wednesday and will hopefully resolve the problem. Will post again after I have driven for a while.

Cheers.

Did changing the throttle body cure the problem, I hope so buddy.