NefMoto

Technical => Diagnostics => Topic started by: zaoxdk on October 06, 2019, 01:30:17 AM



Title: P0299 Underboost N75 problem 1.8T
Post by: zaoxdk on October 06, 2019, 01:30:17 AM
Hello
I have had problems with not achieving the correct boost (file set to 1.1 bar) car only boosts 0.5-0.6 which is the wastegate opening pressure. The turbo which I have mounted is a K04-015. I have checked that it has the same wastegate opening pressure as on the Stock turbo.
Car is a A4 B6 1.8t BFB, 518AL. When disconnecting the wastegate actuator hose from N75, it boosts fine (above 1.1 ofc). The N75 is mounted as it should, triple checked that. It’s a brand new OE unit.
No boost leaks, have FMIC or restrictions in exhaust.

Has anyone experienced the same?
Thanks


Title: Re: P0299 Underboost N75 problem 1.8T
Post by: fukenbroken on October 06, 2019, 02:46:24 AM
it should push much more than 1.1 wo actuator line
post logs etc


Title: Re: P0299 Underboost N75 problem 1.8T
Post by: zaoxdk on October 06, 2019, 03:47:43 AM
It does. Haven’t got any logs yet. Got it pushing at least 1.5 on the dyno W/O wastegate actuator line, but I let it off as I am on stock rods.


Title: Re: P0299 Underboost N75 problem 1.8T
Post by: nyet on October 06, 2019, 07:12:51 AM
Pointless asking for help until you post logs. In fact, it is a forum rule

http://nefariousmotorsports.com/forum/index.php?topic=5295.0title=


Title: Re: P0299 Underboost N75 problem 1.8T
Post by: zaoxdk on October 06, 2019, 02:36:11 PM
Will get some logs then. Sorry for breaking forum rulles.


Title: Re: P0299 Underboost N75 problem 1.8T
Post by: zaoxdk on October 10, 2019, 02:24:47 AM
Problem solved. Fitted N75 valve from a A3 8P 2.0tfsi. OE num: 06F906283F. Had to rewire the plug to a different D type connector. This valve is also much cheaper than the old style n75. Car boosts fine and holds at 1.1 as programmed.

System has been tested up to 2.5 bar - no leaks were found.

For some odd reason, the brand new OEM N75 which i had fitted must have had some problems, as it simply wouldn’t bleed enough air into the atmospheric pressure pipe.Measuring pressure at 95% n75 duty cycle at actutator connection (T pipe to a pressure gauge) resulted in 0.4-0.5 which is more than enough to open the wastegate.

Wastegate has been checked with a pressure gun, and has same opening pressure (0.5) as Stock turbo.

For any more info, please ask.


Title: Re: P0299 Underboost N75 problem 1.8T
Post by: Marty on October 10, 2019, 05:11:56 AM
Do an output test with vcds verify its working. Did you wore it backwards? They wont work right if polarity is incorrect


Title: Re: P0299 Underboost N75 problem 1.8T
Post by: zaoxdk on October 10, 2019, 06:14:39 AM
Yes, it is functioning as it should, dutycycle is not as High as on the Stock n75, while boost request matches boost actual. Has been wired correctly, checked polarity on diagram and valve