Stall During Deceleration when Disengaging Clutch
Posted: Fri Jul 05, 2019 6:42 am
Hi All,
Quick overview per forum rules:
- Vehicle: 2003 Acura RSX Base
- K-Pro Serial Number: 47443
- KManager Version: 4.3.5.0
- ECU part number/serial number: 37820-PND-A03 / 2062-200505
- K-Pro purchased through HPTautosport (authorized dealer) in March 2018
- Numerous modifications, most relevant to issue include:
-Forged K20A3 rods and pistons (stock K20A3 crank)
-CXRacing Turbo Kit
-EP3 5-speed Stock Transmission (auto to manual swap)
-ACT AR1-HDSS clutch paired with Exedy HF02 lightweight flywheel
-BC0051 Stage 2 Cams paired with BC0050 Springs/Retainers
-80 lb/hr injectors (similar to RC style injectors)
-DW65c fuel pump
- Datalog and related calibration attached
The issue I am having is that my engine will stall (quite repeatably) whenever I disengage the clutch during a deceleration with throttle off around the 1200-2500 rpm range. The chance of stall dramatically increases with accessory load (particularly air conditioning). With the lightweight flywheel I'm using (and somewhat regret for my application), it appears as though the IACV cannot catch idle quickly enough to prevent the stall, and the stall happens extremely quickly when clutching in.
I have tried a cleaned and new IACV, cleaned the throttle body, made minor adjustments to the throttle stop screw, re-calibrated the TPS numerous times, checked vacuum connections, and tried multiple iterations of the IAC duty cycle adjustment. So far, none of these attempts have made any detectable impact on the stalling issue.
For reference, if I allow the revs to drop to nearly idle (down to ~1,000 RPM with idle set at 925), this issue rarely (if ever) happens. This just isn't a practical solution for daily driving, which is the intended use of my car.
Also, the calibration attached is locked in to the 0° cam angle, since that is what I'm currently tuning, but this issue has always existed in all of the calibrations I've used.
I have seen many threads on various forums that describe similar problems, but I've yet to encounter anyone posting a definitive solution. I am currently suspecting that the lightweight flywheel is the majority of the problem for my application, but I'm also curious if this is strictly exaggerating some other underlying issue.
Does anyone have any suggestions for something else I can try in K-Pro?
Thanks for reading!
Quick overview per forum rules:
- Vehicle: 2003 Acura RSX Base
- K-Pro Serial Number: 47443
- KManager Version: 4.3.5.0
- ECU part number/serial number: 37820-PND-A03 / 2062-200505
- K-Pro purchased through HPTautosport (authorized dealer) in March 2018
- Numerous modifications, most relevant to issue include:
-Forged K20A3 rods and pistons (stock K20A3 crank)
-CXRacing Turbo Kit
-EP3 5-speed Stock Transmission (auto to manual swap)
-ACT AR1-HDSS clutch paired with Exedy HF02 lightweight flywheel
-BC0051 Stage 2 Cams paired with BC0050 Springs/Retainers
-80 lb/hr injectors (similar to RC style injectors)
-DW65c fuel pump
- Datalog and related calibration attached
The issue I am having is that my engine will stall (quite repeatably) whenever I disengage the clutch during a deceleration with throttle off around the 1200-2500 rpm range. The chance of stall dramatically increases with accessory load (particularly air conditioning). With the lightweight flywheel I'm using (and somewhat regret for my application), it appears as though the IACV cannot catch idle quickly enough to prevent the stall, and the stall happens extremely quickly when clutching in.
I have tried a cleaned and new IACV, cleaned the throttle body, made minor adjustments to the throttle stop screw, re-calibrated the TPS numerous times, checked vacuum connections, and tried multiple iterations of the IAC duty cycle adjustment. So far, none of these attempts have made any detectable impact on the stalling issue.
For reference, if I allow the revs to drop to nearly idle (down to ~1,000 RPM with idle set at 925), this issue rarely (if ever) happens. This just isn't a practical solution for daily driving, which is the intended use of my car.
Also, the calibration attached is locked in to the 0° cam angle, since that is what I'm currently tuning, but this issue has always existed in all of the calibrations I've used.
I have seen many threads on various forums that describe similar problems, but I've yet to encounter anyone posting a definitive solution. I am currently suspecting that the lightweight flywheel is the majority of the problem for my application, but I'm also curious if this is strictly exaggerating some other underlying issue.
Does anyone have any suggestions for something else I can try in K-Pro?
Thanks for reading!