1.9 TDI AFN 110 boost control problem, help
Just wondering if anyone can help, got a boost control issue since i've cleaned out the VNT.
Anyway my issue is this, I have a boost guage fitted so i knew previous pressures etc, since i re-built the head and cleaned out the turbo it's been high boosting 20+psi @ motorway speeds on full throttle it will instantaniously hit 30psi!!!!
This is not good atall! and thus limp home mode has activated twice.
So i've been driving with a carefull eye on the boost until i had a chance to change the actuator setting as i think i freed it's movement to easily when re-building it.
Since i adjusted the boost (took a few adjustments to get it right) it now boosts ok (not over 20psi) tho the N75 and actuator seem to have no adjustment ie as if the N75 is not working as there is now no vacuum going to the actuator on idle as there was in previous tests.
The result is the car has the vanes set at one position, and is very laggy, boost no longer picks up on throttle but is more according to revs.
But not having any fault codes to read? i'm poking around in the dark.
An idea for you of the tune:
110 bhp Audi A6 1.9 TDi
S/S cat back Exhaut
EGR disconnected (but not blanked ATM)
Just done head re-con and Turbo VNT cleanout.
I've double and tripple checked the vacuum pipes and electrical connections and cannot see anything amiss there.
I'm stumped really, and until i get fault codes read i'm a bit stuck but i'm sure that will throw up loads of stuff which will be indecisive of the issue i'm sure.
I'm sure it's nothing to do with the maf/fueling as when on boost (above 2200rpm) it performs well and i can still overtake at less than motorway speeds, but @ 70mph boost is at 20psi (full throttle) still (obiously no VNT correction happening) and will go in limp mode, which limits fuelling aswell as boost hits 9-10psi but if u floor it performance is worse than "light footing it" as i call it.
Anyway anyhelp much appreciated.