Hi guys. was wondering if you could help me solve a problem thats driving me crazy. here goes...I own a R reg escort mk6 gti, it's been modifed a bit including KENT RALLY CAMS,BURTON POWER CYLINDER HEAD STAGE 1 and all the other usual bolt -on stuff. but i've not changed anything to do with the ecu,fueling etc. here's the problem, it's only been happeingfor the last 3 months.
If i put my foot flat on the throttle in any gear i get a severe flat spot after around 3000-3500 rpm, which last all the way through the rev range, but if i lift my foot up say half an inch, the power comes back in and everything is fine. I've been told that it's due to the cams opening the valves for longer, which makes the engine need more fuel than in it's current map can supply straight away.
I've also been told that the advance curve(unsure what this is) is wrong and the car needs a remap and a chip.
is there any truth in these comments? can you guys
recommend anything that may help? a huge thanks to anyone that replies.

thanks again.
~david