I'm assuming that you've cleaned the banjo fitting. Maybe your switchover valve is venting everything to the atmosphere? You must have bypassed this when you tested your turbo, so did you notice a change when you hooked it back up? Since you're getting some boost, the turbo must be spinning.

Craig

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1994 E420, Pearl Black/Black. 2.82 rear diff., AMG front spoiler, painted lower half. SOLD

1972 & 1974 BMW 2002tii's.