car stumbling under load 3k and up
 

can anyone help?my car has developed a stumble /hesitation from 3k-5k rpm and after that it isnt as bad but still noticeable,ive changed the plugs and leads which seems to cure it for about 50 miles then goes back to stumble mode,ive also changed the coil pack(no change)my mods are intake,downpipe,midpipe,blitz catback,mild port,fmic,fpr and 1200cc sec inj,air/fuel 11-1 @11.5 psi.It does feel worse at full throttle/full boost but only after 3k rpm. Thanks for any help,Roy uk.

sorry,forgot to mention power fc aswell

did you change the wires?

yes new magnecor kv85 leads.Please look at dyno graph to show lambda peaks.

Its pretty rich in the 3k range, but not terribly so.

its the little lean spikes at 3200.3900,4600,5400,6200 and 6900rpm.Trying to find out what spikes are.