On my way up to ctown last night then today i have noticed my TF sports..... when in cruise control on i can be on a straight flat bit of road and it would go from 100 down to 90 sit on 90 for a bit then back upto 100 i never had a problem with this in my TE......can anyone shed some light on it for me PLZZZZZZ......

Guys, Tech section = No Spam, not sure if there is also help needed understanding that as well.....posts have been deleted

Now to actually try and assist, there are generally 2 things that can cause this, the vac pump may be on its way out, this will generally be the first issue that arrises when it is failing. The second is the vac system, ie the vac line and the diaphram on the TB, if either has a hole it will not hold vacuum and thus drop speed, the Cruise ecu will detect the drop and try and bring speed up to the preset.

Get the second part tested first and if passes look to getting a new or secondhand pump

Hmmm ok ill take it to where i take my car tooo Its only just started happening and its not all the time but yeah just threw me you know driving along at 100 and then slows down to 90 im worried someone behind wont notice and run up the back of me :(