Ok since owning my Gsi iv had nothing but probs but i only have 2 left yay!! One of them is the power sounder which i asked about in the electrical forum.
Anyway, the second one is as follows:
Rather than going flat-out if you slowly increase the throttle so the revs climb slowly my car seems to produce power in waves. If i watch my boost gauge it boosts to 15PSi (got regal remap by previous owner) then drops off to 0PSi and then boosts to 15PSi and drops off to 0PSi right through the rev range. On full throttle its fine overboosts to 15Psi and then comes back to about 11Psi and holds steady.
Im thinking boost solenoid probs??