eg d15 flat spot in acceleration

[tottitomo]

I have a 94 eg with a d15b7 manual,

When taking off first is fine then second acceleration stops and has flat spot I would say it’s around 2500-3000rpm with your foot flat to the floor nothing then all of the sudden it will rocket off... or you change in to third its usually fine too, it’s been like this since I got it and it doesn’t happen all the time.

I’ve changed:
Spark plugs
Leads
coil
Fuel pump
Fuel filter
Earth straps off gear box and rocker cover
Air filter
timing belt
Changed injectors
Reset ecu
Cleaned throttle body
Checked ignition timing

Is there anything else anyone can think of and does anyone have the same problem

thanks Rhys