Throttle cut/boost issue...

[jaredsogn]

Hey guys, posted about this the other day, trying to gather some info. I have 997/K04 hybrids I just put in. Turbos are spiking to about 24 PSI, then dropping to 10 or 15, back up to 24, down to 10 or 15, back up...etc. It seems like the car runs strong every once in a while for about the first pull I do, then it runs poorly like this. Anyone have ideas of what to check, what could be wrong? I pressure tested and didn't find any leaks. Any suggestions are welcome, and please let me know what you think about the logs, does the N75 duty cycle look normal?


Log of throttle angle when it seemed to run ok:




And the rest of the logs are when it was running poorly, cutting throttle, etc...

[highPSI-S4]

I can't be much help, but to better assist you with your issue's it would be good to list all supporting mods to the car.

[jaredsogn]

Mods done to car are:

Darintake
Piggie Pipes
997/K04 hybrids
10secs4 fueling
Stock exhaust with resonator removed

[haus4]

there is definitely something wrong with the throttle response. either gas pedal is messed up or something related to your tune. Btw, wat tune are you running?

[jaredsogn]

Well, my thoughts we more leaning towards throttle cut induced by overboosting...so I was thinking maybe the N75? I am trying to borrow one to test if that is the problem or not...and I am running the 10secS4 hybrid file.

[gointoscott]

throwing any codes?

[///M3 TO S4]

I have a very similar issue, i'm swapping my N75 valve for my buddies, i'll report back to you this weekend. It's quite an annoying issue. My boost will spike up to 24-25, fall to like 15, then near redline go back up to 23-25lbs

[jaredsogn]

I have a very similar issue, i'm swapping my N75 valve for my buddies, i'll report back to you this weekend. It's quite an annoying issue. My boost will spike up to 24-25, fall to like 15, then near redline go back up to 23-25lbs

Alright thanks! Let me know what you find out. It is annoying the heck out of me, because an easy way to describe it, is it feels like you are shifting gears every second...so it feels really slow. I ordered a MBC as well to see if running it in parallel will maybe help?

[jaredsogn]

I have a very similar issue, i'm swapping my N75 valve for my buddies, i'll report back to you this weekend. It's quite an annoying issue. My boost will spike up to 24-25, fall to like 15, then near redline go back up to 23-25lbs

By the way, what setup do you have for turbos and fueling?

[///M3 TO S4]

By the way, what setup do you have for turbos and fueling?

awe fuel with the electronic boost controller option set higher than what it comes with....PJ K04's

[spinny]

See my post on AW..

Also, I'm running a 1.8T N75 race valve.

My car spikes to 23 and just holds 23.

[jaredsogn]

See my post on AW..

Also, I'm running a 1.8T N75 race valve.

My car spikes to 23 and just holds 23.

Which post are you talking about?

[spinny]

Which post are you talking about?

I replied to you over at AW, spinny201 is my username there.

[xtort44]

my car is doing this too. Anyone come to a conclusion. Running OTS complete AWE rsk04 kit.

[NogaroWonda00]

Well, my thoughts we more leaning towards throttle cut induced by overboosting...so I was thinking maybe the N75? I am trying to borrow one to test if that is the problem or not...and I am running the 10secS4 hybrid file.

there is a good possibility your on the right track, id also pull the plugs and check the gap, and the coil packs. clean your maf sensor with some throttle-body parts cleaner too.

is it cutting out right at/after full boost hits or on the way to boost?
any missfire codes as well?

[RickS4]

I think about overboost. Request vs actual = To much difference.
i put an MBC on mine for cut my pike and now 0 throttle cut.

PS, How do you made this diagram? Which software.
Thanks!

[Tifosi]

my car is doing this too. Anyone come to a conclusion. Running OTS complete AWE rsk04 kit.

What ICs are you running, AWE ?

[audiSUKKA]

I think it could be the 02 sensor.

[///M3 TO S4]

I think it could be the 02 sensor.

no....not even close

[AudiSportB5S4]

Old thread!

Since then Jared has switched to a VAST Tune running strong!

[xtort44]

What ICs are you running, AWE ?

ER IC's

[xtort44]

FWIW put in a new, well used, n75 and my problems disappeared. Special thanks goes to thirdstrike for helping me out.

[gointoscott]

new, well used

lol that sounds a little contradictory. But glad to see its fixed.

[xtort44]

had it sitting around so figured why not give it a shot. can't beat free!