Wild oscillations on WGDC - Boost Leak or something else? - N54Tech.com

brittom · 2020-07-11 17_38_01.csv (1.1 KB, 41 views)

Hello all. I've never posted here before, as I've always been able to find the info I need for whatever I've been experiencing (Thanks! You guys are awesome!). For this latest issue, however, I've not been able to find a definitive answer. I'm experiencing "surging" under heavy acceleration, and when I log the run it seems it's due to really wild fluctuations in the waste gate duty cycle (wgdc). Some times it is worse than others. Stuff I've read seems to suggest boost leak, but I've not seen anyone post duty cycle fluctuations as large as the ones I'm seeing on my car. Thoughts?

BeatupVR4 · 07-28-2020, 04:21 AM

I've never messed with my JB4 apart from the steering wheel controls but looking at that purely from a process control point of view it looks like a PID controller with values that are way off. Are there control values for the boost control that you set?

I am fairly well versed in ECMLink and Evoscan/flash and this happens a lot with new tuners.

brittom · 07-28-2020, 05:14 AM

I've just been running the stock maps (typically 1 or 5) with no back end flash. I've never gone into setting my own control values. I'll double check to make sure that something hasn't inadvertently made it's way in there.

BeatupVR4 · 07-28-2020, 06:21 AM

I've only done the exact same thing. Was there any recent work you did to the car that could have possibly caused the issue?

brittom · 07-28-2020, 07:16 AM

I've had this issue for a while. I recently replaced the injectors with index 12, but I had the issue occurring before then.

brittom · 08-24-2020, 10:44 AM

I've now also replaced the HPFP (not for this issue, btw) and charge pipe, and still having same issue. Could a vacuum leak be causing this?