Any advice with this problem would be much appreciated.
I have a uk95 4 door which appears standard except for a numatics valve under the bonnet and loose carpet in the passenger footwell. I am told this means it has been chipped so I have turned the screw in the numatics valve fully clockwise until I can get a superchips man to check it over.
The car misfires around the 1000-2000 revs mark under acceleration. The problem doesn't occur when cold, or higher in the rev range. The service hist indicates the plugs were done at 80,000 (car has 95,000 on the clock).
Most misfires I have read about are higher in the rev range, so any ideas anyone?
By the way car has just had an oil change and cam belt... made no difference to the problem. Idles fine and always starts first time.

 

The loose carpet is more likely because the old owner was married to a lard ar*e!