Strange things going on

[Edhertz]

Strange things going on here with my Xantia. At start up from cold the engine speed is a little highish at 1200 ish with no evidence of cable sticking or dragging ie good response. With car underway at around 2500 revs, I lift my foot off the pedal to decelerate and nothing happens ie revs stay where they are. Whilst at this speed I select neutral, take my foot off the accelerator and revs stay where they are. The only way I can reduce the engine speed is by means of the brake. At stop the idle speed returns to 1200 ish. If I then turn off and let it stand for a while and turn on again, engine speed goes to 950, all strange behaviour gone and no faults on Lexia. Hope this makes some sort of sense to someone and thanks in advance.

[Sloppysod]

Just a thought, is the cokdstart system stuck? Possibly due to a sign from a temperature sender, engine, air inlet or radiator?
Maybe worth a look.
Sent from my mobile phone with predictive text turned no

[Edhertz]

Thanks for reply. The answer was a duff MAF sensor. Changed for new and everything is back to normal.