Im not looking for suggestions such as boost leak, or a cracked hose.....

I want to know what can cause a car to have extreme boost lag develop over the course of 2 days after running perfectly.

Has nothing do to with the ECU, injectors, N249, intake leak.


TIA

 

MAF?? be my best guess. or something wiht the fuel pump/area

 

Im not getting any DTC codes...wouldnt these throw a code or cause a no-start?

Could the MAf be malfunctioning without throwing a DTC?

 

hmm.. Im not positive on that.. i would think yes it can. But not sure.

Can you explain your symptoms a bit more.... Is it jerking at all or does it just not seem all there..or doesnt spool.. Jsut a bit more descriptive would be good.

 

well, for example in a low gear at around 3500rpm...

i will go WOT and the turbo will spool to 0 psi, from 20mm/hg vacuum
it will sit at 0 psi for a few hundred rpm and slowly creep up to 2 or 3 psi.

then it starts bouncing up and down between 5 and 10 psi, very irregular.

no intake leaks...brand new hyperboost DVs....brand new K04s and clutch.

problem began about 2 days after installing MBC-only. Replaced MBC with stock N75 and problem persists.

 

could be in that limp mode... try a search on that or on audizine/audiworld.

 

limp mode it wud sppol normal speed but stop at 5 psi. the car isnt building boost as it should be.

 

well..how long you taking to get to your 5 psi.. i mean you can run through gears pretty quick..

 

no theres a straing hesitation during boost building. the turbo spools to 0 at normal speed but then there is something holding back boost,

proved that by logging 115 (actual vs. requested boost)

 

is it almost like its bogging out?? outside of a hose detaced or a boost leak my guess still is the maf.