Yes with now multiscan boost solenoid test is with engine off i think also, it makes diy watching operation a bit tricky.
Best to have engine running, get ready to do test stop engine and do test asap before vac runs out.i think solenoid operates a few times but im sure vac runs out after 1-2 cycles, restart car and repeat to rebuild some vac.
Im guessing a garage may have a vac source to connect bu vac pump maybe?
In operation i think its pwm maybe?. And operates between 75% and 20% so not sure on if. Possible to suck blow through, never had mine off.
I usually have engine idling 75% fully pulled in actuator and pull pipe from actuator and watch open out approx 10mm then refit pipe and should pull back in pretty quick.
The slower it pulls back in id be looking for vac leaks also prob.
If you can get hold of a vac gauge it takes just over -0.6 bar to pull vnt to stop screw.
Last edited by sussexa; 07-12-12 at 15:57.