varying boost - what to log

cleaver · August 13th, 2009, 05:39

I have issues with my boost at WOT. It bounces from 6-20psi...I just replaced the VNT actuator and all hoses.

I am going to use VCDS to get some more info, what should I log?

Curious Chris · August 13th, 2009, 08:30

Log MAF specified, MAF Actual, MAP specified, MAP actual, and throttle position. Then warm engine, 3rd gear, 100% throttle, 2000-5000 rpm, repeat 3 or 4 times.

I am guessing either boost system leak or screwy MAF. I have seen screwy MAF's that bounce all over causing boost to jump up and down. I also had a OMI break a bracket that gave me an intermittent leak and cause my boost to meander. The 100% throttle eliminates adaptation.