97 a4 1.8t. Some of the time I have no boost. Some of the time the turbo works perfect. Most of the time though when the turbo is working I get a hard bucking or jerking! No vac leaks. Perfect 60 fuel pressure. New ecu which mechanic thought would fix the problem but didn't. Dunno if unrelated but oil temp never goes up on gauge.My mechanic is making this his project but cant figure it out so far?