llxkevinxll
10+ Year Contributor
- 581
- 309
- Jan 29, 2012
-
Milwaukee,
Wisconsin
I am a bit stumped on this idle control issue on my 2G running a Haltech Elite.
Relevant mods/components:
100% stock late 2G 7 bolt engine
FIC 1650 High-Zs
Aeromotive AFPR set at 50 psi Injector Pressure Differential
AEM 5 bar MAP
Haltech CAN Wideband with the Bosch LSU 4.9 sensor
4G Eclipse DBW throttle body
This screenshot shows the basic issue. Idle is stable, trims are reasonable, no issues. After a brief blip of the throttle and small delay, the trims start swinging negative and you can see the idle quality (RPM fluctiations) increase in magnitude roughly 2x. In person, this results in a noticeably choppy idle compared to prior to that throttle blip. I also noticed the fuel injector pulse width drops and stays below the values where the idle was stable. I am using the Haltech default Bosch 1650 settings for flow and dead time. I had been using the provided FIC numbers for my set but I see the same symptoms. In this specific case I induced this behavior with throttle action but I also see this occur during a normal warmup where I start the car and literally let it sit at idle without touching anything. Right around thermostat temp, the trims swing negative and idle rpm starts hunting. I have attached (in a ZIP, the website didn't like the extension/size of the individual files) the full PC log (all ECU parameters) and the HLGZIP which contains the calibration itself along with the logged data for use within the NSP software.
Things I have tried:
Disabling the Fuel Film model function
Disabling Predicted MAP (transient throttle)
Raising/lowering base fuel pressure
Raising/lowering the target idle rpm
Changing injector dead times
Changing injector flow rate values
Changing/zeroing short pulse width adder values
I would appreciate any insight into this minor (but annoying) issue. Thanks!
Relevant mods/components:
100% stock late 2G 7 bolt engine
FIC 1650 High-Zs
Aeromotive AFPR set at 50 psi Injector Pressure Differential
AEM 5 bar MAP
Haltech CAN Wideband with the Bosch LSU 4.9 sensor
4G Eclipse DBW throttle body
This screenshot shows the basic issue. Idle is stable, trims are reasonable, no issues. After a brief blip of the throttle and small delay, the trims start swinging negative and you can see the idle quality (RPM fluctiations) increase in magnitude roughly 2x. In person, this results in a noticeably choppy idle compared to prior to that throttle blip. I also noticed the fuel injector pulse width drops and stays below the values where the idle was stable. I am using the Haltech default Bosch 1650 settings for flow and dead time. I had been using the provided FIC numbers for my set but I see the same symptoms. In this specific case I induced this behavior with throttle action but I also see this occur during a normal warmup where I start the car and literally let it sit at idle without touching anything. Right around thermostat temp, the trims swing negative and idle rpm starts hunting. I have attached (in a ZIP, the website didn't like the extension/size of the individual files) the full PC log (all ECU parameters) and the HLGZIP which contains the calibration itself along with the logged data for use within the NSP software.
Things I have tried:
Disabling the Fuel Film model function
Disabling Predicted MAP (transient throttle)
Raising/lowering base fuel pressure
Raising/lowering the target idle rpm
Changing injector dead times
Changing injector flow rate values
Changing/zeroing short pulse width adder values
I would appreciate any insight into this minor (but annoying) issue. Thanks!
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