Just fitted a boost controller to by B5 A4 1.8 t its a 98 model problem im having is that when i alter thecontroller to give me more boost the car lurches forward like its running out of petrol but its fine when u turn it back to normalanybody have an idea how this seems to be happening ?

 

How much extra boost are you giving it? You could you be maxing out your injectors or fuel pump.

 

What kind of boost controler did you get? I'm no tech but, I know the stock injectors are only 180cc which are small.
My brothers stock injectors on this 240sx were 370cc. So, I'd have to go with BAMF. Also, maybe your FPR is on it's way out. Do you have any other mod's? Stock turbo?

 

Sounds like throttle cut.