K04 upgrade low boost issues.

Good Afternoon,

I have installed a unitronic K04 turbo kit to a customers Audi TT 2.0tfsi, upgrading it from the IHI fitted unit. We received the car with the turbo removed by another garage as it had failed and separated then the customer decided to upgrade.

I have started trying to tune and installed the base map but it will not boost over 0.5bar and gets the DTC P0299 for low boost. I have replaced the boost solenoid valve, diverter valve with units I had in stock. I have compression tested and get 11.5 bar on all 4 cylinders which is in spec, but cyl 2 and 3 have some oil in them but I know these engine can be bad for burning and passing oil.

I have smoke tested and pressure tested the system and there are no leaks, Data logging on VCDS shows wastegate duty is at 95% whilst trying to make boost of 2000mbar (1 bar) but it peaks at 1500mbar (0.5bar). If I remove the hose from the actuator boost peaks at around 2500mbar. Connecting it to the boost sensor on the dyno it hits about 1.6bar then flutters between 1.4 and 1.6bar. With no boost control Id of thought this would try peak to over 2bar and build boost a lot higher at lower rpm rather than climb from 0.8bar to 1.4bar progressively during a WOT run.

Has anyone seen an issue like this before? It is a brand new turbo fitted but engine condition is not known. Could damaged engine cause a boost issue or likely to be a faulty turbo?

ECU is a MED17.1

Any advice much appreciated.

Daniel

It sounds like you're getting spring pressure then some boost creep with everything hooked up, and when you pull the WG actuator hose you get more boost?

Is throttle staying open?

If so, have you verified the solenoid is receiving good power, and ground is actually cycling providing 95% duty?

Hose routing is ok?