Have an interesting little nuisance I'm working on. Every once in awhile, I get a rapid throttle oscillation. When it happens, it occurs just off idle if I'm trying to creep the car forward or I clutch in around 2000 rpm when slowing to a stop. MAF and VVE tables all look good and the VTT seems to be pretty good as well. If needed I can provide a much larger section of the log file.
99% of the time the all is good. I've attached the current tune and a couple minute snippet of a much longer (40 min) file. About 55 seconds into the snippet is where the oscillation begins. You can see the ECM adjusting timing and throttle to try and catch it. Off the cuff I'm guessing I need to increase the spark adaptive a little more and reduce the throttle. Before I go messing around more with the adaptives, I thought I'd ask for a second set of eyes to take a look. Unfortunately I'm super time-constrained at home with some family matters so a bunch of experiments are difficult to fit in. You'll note I'm on Rev 40 of the tune...lots of past experimentation...just no time to do so currently.
Car/Mods
2019 Corvette Grand Sport with the LT1 and 7spd manual transmission.
- Ported cylinder heads
- Nick Williams 103mm throttle body
- Mamo ported MSD intake manifold
- AFE cold air intake
- LG full length headers
- G-sport (GESI) Gen 2 cats rated at 500hp/bank
- DoD deleted
- GPI SS3 LT cam (pic of cam card below)
- RPS Billet Carbon Street Twin Clutch w/Aluminum Flywheel (>40lbs lighter than stock)
Screenshot 2024-01-03 121753 - Throttle Oscillation.png
2024-01-01 R40.hpt
2024-01-02 R40 Throttle Fluctuation.hpl