I have a large turbo escort its been chipped with greens and 3 map bar sensor and what have ya the prob is you cant put your foot down because as the turbo winds up it cuts out and coughs and splutters running about 24psi so the last keeper said is it over boosting?

 

have u tryed changein ur plugs ? mine did the same thing an i had 2 put uprated 1,s in ngk 9 i think

 

i havent tried that mate only just got the car, SCC said it needs setting up maybe running too much boost

 

Yeah m8, its hitting the boost limiter, the actuator could have gone weak, or as with mine it could be a problem with the chip, or it may just want the boost backing off a bit.......my money is on the actuator.

Pete.