What is "Surging"
 

Been told my car is surging. !!!

Basically under hard acceleration, turbo spins up and once turbo gauge hits 1.3 bar, it drops back to about 1.0 - 1.3 bar

Its hissing at about 3750-4000rpm under load.

I have checked pipes, and cleaned out boost solenoid. No change.

unplugged MAF while car ticking over and no change, but then dont think BUG EYES MAF, is same as classic shape so perhaps engine wont hunt when MAF disconnected.

Are there any hoses under I/C that could be culprit, as I have checked the ones from airfilter to turbo, and pipes to actuator.

Need help on this one. Its running Full MOTEC M800 GOLD BOX.

What would the Lamda sensor cause if its failing ? noise etc..etc....

Been informed that its on the pressure side of the turbo not inlet. Could the dump valve be opening early. Is the actuator the dump valve ?

Help Please.... (its a Subaru s202)

Regards

Joolz

Please...anyone ?