[Mayuri Krab]

Hi guys,

I did a google search on n54 pulsating boost issue but all of the ones I have seen are regarding the pulsating issue happening under heavy acceleration or WOT, which is completely the different of what is happening in my case.

Basically mine is happening only at very light throttle/load (<20% throttle, car's only boosting to ~2-3psi), I hijacked the fuel gauge using JB4 & basically when this is happening the boost goes up to ~2psi & then drop back to 0 & repeat while the car accelerating. At the same time you could hear the induction sound from the DCI pulsating as well.

Typical case when this happens is if I was crusing along at 60km/h in normal D mode (so 6th gear) & put my foot down slightly (<20% throttle) to overtake someone (still in 6th gear).

However as soon as I give it more throttle this pulsating thing disappears, induction sound is one constant air sucking noise & the boost (according to the hijacked gauge) stays at a constant 5psi or higher depending on much more throttle I use.

Also car WOTs fine (& hits the target 14.5psi for JB4 map 2 no problem) & so far is not giving any CEL errors.

Any ideas what I should be checking?

Cheers.

[135Pats]

So you are tuning using solely a JB? Oscillations can be caused by several things, could be PID control down low, could just be the tuning (I strongly doubt that with a piggy controlling the gates). I'd be interested to see how much the throttle plate is trimming when you're feeling that oscillation.

[Mike@N54Tuning.com]

Throw a JB4 CSV log of the issue in the n54tech support section and I'm sure they can tell you how to correct for it.

Mike

[musc]

Log it as Mike said. If it's under 20% throttle then adjusting Menu 10 and 12 may help. Beyond 20% those menus wont have any effect per Terry.