This is the bane of my life, not long had the car back and still the flat spot is there, anyone know what causes a flat spot? like before the affected rpm's are now 3k - 4k where i should be getting power instead im getting sweet FA

i have been given this for reasons why the flat spot is there

in for a penny in for a pound
new
solenoid
variator
cam belt
rocker gasket
service it too.

any truth? this gonna be a costly jobbie?

Out of interest what's a flat spot? I think I have the same in my Panda, I've always refered to it as hesitation, can happen when moving off, at 2,000rpm, and 5,000rpm, and I've been told it's probably the Lambda sensor.

Jon.