i have a x plate astra sri runnin a standard x20xev with 103k on the clock and it has a flat spot between 2500-4000rpm.

was just wondering if this is common and if there is any way of getting rid of it.i have done a full service with plugs, leads and new coil pack,air filter fuel filter.

im tempted to replace the injectors to see if this would atleast shorten the flat spot range then fit a adjustable fuel regulator and get her sat on a R/R.do you think that this would sort the flat spot out and try and get back some of my lost horses from age?

i know that my astra should be at 136bhp and it does go well but i feel that there is plenty more horses available in the engine.