Hi,iv recently brought a frst and its just started overboosting/backfiring,its got a 195 chip baige injectors t3 has a got a bleed valve fitted"witch iv not touched" any ideas of the cause cheers

 

Sounds like the overboost is kicking in, the signal will come from the ecu I suspect.Alternatively maybe the boost level is set to high and may need to adjust it on the actuator to drop the boost a touch.
You need to know how much boost it is supposed to be running firstly, secondly check it on the boost guage,I'm assuming you have one on the car.You could have an air leak and hencethe turbo could be overspeeding possibly leading to overboost.

Finally I would get the car set up by a specialist to check boost and AFR levels etc especially if you have just purchased the car in your case.A good set up by a specialist is worth it's weight in gold.
I hope this helps.

Thanks. Lee.

 

As 1374Lee has said get it checked asap, if its overboosting it could lead to major engine problems.A melted plug/hole in piston worst case scenario!!!

 

Checked for air leaks today nothing found,it peaks at 18psi and hold 14psi only does it when hot really,where is best place to take it to get set up I live on isle of wight so nearest possible would be great thanks ben