Confused by boost fluctuation

[Gewehr455]

Recently my TTA has been experiencing boost fluctuation when I floor it. As the boost climbs it will slowly fluctuate back and forth between 12-18 pounds under wot. There is no consistency to the way it fluctuates. I thought maybe a vacuum/boost leak? I recently changed the hoses that come from the vacuum block as they looked somewhat crummy, but this didn't help. Everything that I can see looks tight. Today I changed the wastegate hoses to a new set and changed the pcv and its hose. Didn't help either. My scanmaster doesn't show any codes. The cars mods are an upgraded fuel pump, hotwire kit, adjustable wastgate, K&N air filter, valve cover breather, RJC powerplate and chip. Anyone have any ideas?


Jim

 

[Sweet6]

Try the RJC manual boost controller. Or bypass the Y hose and run a vacuum hose from the compressor to the actuator. The boost will run off whatever the WG is set at. That will take the ECM out of the picture for boost control. If you still have a problem then there might be some air restrictions somewhere.

 

[2QUIK6]

Maybe MAF dropout if you are maxing the MAF at 255 gpms. Boost slowly fluctuating is a symptom of that. Using an Translator will cure it, or an aftermarket chip which locks the MAF at 255 at WOT. Mine did it real bad just like that from 12-18 with a bigger than stock turbo...I used a Thrasher chip to cure the dropout.