Boost Issues.

[Feint S12]

I'm getting negative boost readings on my gauge at idle, however when throttled it returns to zero. No blow off at all. not too sure if there's a vacuum leak or maybe if Im feeding the wrong vacuums? also having weak throttle response, bogs out at roughly 4k RPM as well. I tightened the ignition coils, replaced several vacuum hoses, replaced PCV valve, replaced injectors, redid ignition timing. Just mainly trying to get that turbo blow off going. I used a vacuum gauge where Id get around 20PSI at idle, then it would zero out when throttled. not getting any pressure at intake manifold where wastegate vacuum is connected. any suggestions?

[Jeremy]

Feint,  you are supposed to have a vacuum at idle as the throttle plate is closed( and you have the gauge plumbed after the throttle plate.  then when free revving it should ( depending on turbo size ) it should come up to about zero or atmospheric pressure, and there should not be any blow off sound as that is supposed to happen when you are at positive pressure, and snap close the throttle. so where is your wastegate actuator plumbed?

[StephenG]

Take it around the block and watch it, you should be able to build some boost. You wont see anything until you have a load on the engine.