Problem: Little or no boost, any ideas?
 

Have MY99 UK Impreza with full decat, HKS SSQV VTA Dump valve and TEK 2.5 running 17.5PSI Peak boost.

Yesterday, saw some overboost briefly when accelerating in 4th/5h so eased off right away. Have knockilnk, boost gauge and SECS ecu data monitor with oil pressure/temp add on. Never seen more than one flashing green EVER on knocklink including last night, so don`t suspect I had any det., and SECS unit knock correction showing zero.

Today, the boost was very low, and fluctuating, and now little or no boost at all. Checked there was nothing obvios such as any hoses etc.. off, but am a novice regarding this really. anyone got any ideas or pointers. If I cannot see anything obvious am ringing TSL tomorrow who normally service the car.

Any suggestions, checks much appreciated, event if its to tell me my turbos shot!

Graham

Have you checked that the wastegate actuator arm has popped off, I think it's only held on by a c-clip or similar. This would cause no boost at all as the wastegate would be flapping around, but you would not get any whistling noises as would be associated with a split or popped off pipe. The car would otherwise seem normal?

zhastaph: Thanks for that, I checked the wastegate arm as you sugtgested, and the clip seemed OK. However, after trying to move the arm/mechanism it was stiff, and finally moved but was sticking. Removed the wastegate solenoid and pipes and have them all a good clean using solvent. This freed the mechanism... now back on and boost resumed to normal.

Thanks for the advice, it pointed me in the right direction

Graham