1999 xjr will not rev over 3k

[jas xjr]

my xjr will not rev over 3k revs. what could be the possible cause. it seems to misfire if i try to kickdown from around 70mph . if i try to increase speed gradualy it seems to be ok.thanks in advance

[RW774]

Throttle pot or coils. Might even be the wrong plus fitted.

[NormanD]

Could have gone into 'Limp home mode' if there is something amis

[P700DEE]

Will not go over 3000 unless in drive, so assume your problem is while moving ?

[jas xjr]

P700DEE said:

Will not go over 3000 unless in drive, so assume your problem is while moving ?

not tried revving it in neutral. yes on motorway doing 70 had to move out of the way sharpish, put my foot down and nothing happened. just felt it stutter. the car has been sitting for a while so could be dirty fuel from bottom of the tank. will get it checked over but would like some sort of idea really before i go to thye garage. no warning lights

Edited by jas xjr on Monday 5th October 17:30

[jas xjr]

Bloody thing will not rev over 500 rpm now and will not drive. Just been recovered on back of aa wagon. Aa guy reckons fuel filter. Still no warning lights

[jas xjr]

just had a call from the garage, it was the fuel pump in the petrol tank .

[jas xjr]

replaced fuel pump and the car is running great again. shame about the dark nights and rain