Cutting boost @ 4k rpm

[rhinopower]

i don't know if it's coincidence, but since replacing the broken vac resovoir I have been finding the car cut boost from 1.5bar to 0.5 bar at around 4k rpm.

I'm guessing the ecu is intervening, but can't see anything obvious as to why it would be doing this. I also deleted the sai in the last couple of days, and plugged the hose that went from n249 to n112 valve, which I'm presuming is correct.

 

[rhinopower]

N249 bypassed, and still got the same issue

 

[Mrharris2]

Is the MAF plugged in or working fine silly question I know but I forgot to plug mine in yesterday after a clean and had similar issue full boost but no power after 4k revs maybe a dodgy maf?

 

[JUS3IN]

car is going into safe mode by the sound of it, cuts boost to protect the engine. check all of your work and that the parts you have fitted are correct and fitted right. did you use the right resistors for the sai delete. check all you hoses are not split and scan the car with rosstech.

 

[rhinopower]

By all accounts, its doing the exact same as it was before.... Injector duty cycle was maxing out, so i replaced fuelpump, fitted a 4bar fpr, adjusted settings in unisettings, and i'm still maxing out duty cycle.

 

[JUS3IN]

what power are you at, they max out about 280bhp anyway? unplug you n75 and see if it boosts over 6psi, could be over boosting?

 

[JUS3IN]

what codes are you getting anyway?

 

[rhinopower]

No fault codes at all

 

[JUS3IN]

Maybe the ecu is faulty? Im pretty sure if the car cuts boost it would be logged as a fault... Anyone? Could check the ecu for water ingress... Check and clean the earths under the battery too. Log boost in 3rd gear wot and see whats being requested, Cant remember which block it is, maybe 115? If your cars standard it should be requesting a peak reading at 1800mbs..
If it is its a mechanical issue, next would be to check the actuator pressure, get a tyre valve and work it into the pipe to the actuator and pump it up to 35psi and see if it holds pressure.

 

[rhinopower]

Il get some fresh logs, but still insist it's fueling related given the injectors are maxing out. Maybe I've got a really strong turbo and it's making more boost than the injectors can flow. I want to get it all running correctly so I can book it in for his magic, rather than be 'that guy' that turns up with a big long list of faults and parts that need replacing before mapping starts.