ISCV control system disassembly
Is there any way I can get the AC-enabled idle conditions to max out the stepper assembly? Related to my anti lag thread.
Ive been trying to sort out the thread, but its really unclear, especially since I have 8858 and I think Im missing some def's that arent available.
Full ISC idle in my car is 3100 RPM.
another reiteration of that question is, which table actually relates to increase demand once the AC switch is pressed.
Ive been trying to sort out the thread, but its really unclear, especially since I have 8858 and I think Im missing some def's that arent available.
Full ISC idle in my car is 3100 RPM.
another reiteration of that question is, which table actually relates to increase demand once the AC switch is pressed.
The highest possible ISC step position is definitely 120 steps after some tests I have been working on this week. To log actual ISCV position as a percentage, just use the formula"x*100/120" and use the same request ID as you use for ISC steps.
-Jamie
Ac on error table, do you have any tips to find that table?
8858 has a couple tables undefined yet or overlapping I would like to consolidate my idle section but --
-->
Edit when I changed my ac on table my cts sub 1f2c6 sub 1efc0 table went to 100
8858 has a couple tables undefined yet or overlapping I would like to consolidate my idle section but --
-->Edit when I changed my ac on table my cts sub 1f2c6 sub 1efc0 table went to 100
Last edited by 211Ratsbud; Jan 18, 2013 at 06:15 PM.
ISCV Demand Target Idle Trim (sub_1ECF6) is what its called. I'm not sure if there is a separate one for AC ON and AC OFF like there is in the 9417 roms though.
-Jamie
Dynotech, what particular reason is the ac-on table re-interepeted to be a CTS table? I am missing how an AC on table you want me to adjust correlates to AC on when in the new discovered definitions its not correlated to any thing except coolant temp?
Also on a SD 2.0 baro correction basically has no effect other than if you zero it out then you will lose the correction at the baro you are locked on with the SD settings... correcto?
Oooooh.. I see the RPM adder, maybe I could just set my RPM adder to max demand, and max the steps at that demand, causing no high idle etc... just extreme throttle hang..
Also on a SD 2.0 baro correction basically has no effect other than if you zero it out then you will lose the correction at the baro you are locked on with the SD settings... correcto?
Oooooh.. I see the RPM adder, maybe I could just set my RPM adder to max demand, and max the steps at that demand, causing no high idle etc... just extreme throttle hang..
Last edited by 211Ratsbud; Jan 20, 2013 at 05:21 PM.
Just set the target idle with AC ON to like 9000rpm and set the 'Initial ISCV demand-AC ON' to 100% demand and the idle control valve will always stay wide open with AC ON.
-Jamie
-Jamie
Ok, thank you much.
question:
Why is the max demand you can enter in the table, not the same as the y axis on the stepper table = 102? is it to allow for demand + demand situations? which may sum more than 100?
question:
Why is the max demand you can enter in the table, not the same as the y axis on the stepper table = 102? is it to allow for demand + demand situations? which may sum more than 100?
Last edited by 211Ratsbud; Jan 20, 2013 at 05:35 PM.
The most steps you can have is 120 steps which equals 100% ISC open position. I think it reads 102% demand because the chart is roughly in 4% increments. Regardless, 100%= 100% open position, or damn close to it.
-Jamie
-Jamie
Last edited by Dynotech Tuning; Jan 20, 2013 at 06:33 PM.
I have been having the high start up idle issue coupled with the car dying upon idle down now that it is cold and I am running E85... logged the ISCV trims and they were both about +12%... I went a little different route to get where I wanted to go... BTW car has a Buschur 2.4...
1. Reset all trims
2. Put stock ISCV settings back in place, and reduced the top 4 rows of ISC startup % to 75%
3. Turn the BISS out a lot
4. Put the car in SAS mode and make sure the car is between 750-900 and idles without dying, I did this because everytime I do the BISS adjustment the other way it never seems to work correctly with my car...
5. Take it out of SAS mode and log your trims... adjust ISCV initial steps to get the ISCV steps to around 25 steps
6. After letting the car idle and relearn trims they settled at 2.5 and 2.5... better than 12 and 12..
7. Went for a 20 minute drive to see if the car had any issues with stalling or idle surge and seems to be a lot better... have to wait for the car to cool down so I can see what the RPM is gonna jump to upon initial start up and if it struggles as it idles down... fingers crossed it does not, but with my luck I will have to try a different approach...
1. Reset all trims
2. Put stock ISCV settings back in place, and reduced the top 4 rows of ISC startup % to 75%
3. Turn the BISS out a lot
4. Put the car in SAS mode and make sure the car is between 750-900 and idles without dying, I did this because everytime I do the BISS adjustment the other way it never seems to work correctly with my car...
5. Take it out of SAS mode and log your trims... adjust ISCV initial steps to get the ISCV steps to around 25 steps
6. After letting the car idle and relearn trims they settled at 2.5 and 2.5... better than 12 and 12..
7. Went for a 20 minute drive to see if the car had any issues with stalling or idle surge and seems to be a lot better... have to wait for the car to cool down so I can see what the RPM is gonna jump to upon initial start up and if it struggles as it idles down... fingers crossed it does not, but with my luck I will have to try a different approach...
I'm adding this here since most people are having trouble with startup and focus only on ISCV parameters but thats only 33% of the things you need to focus on. You need to focus on ISCV, Fuel and Timing. All 3 affect idle stability.
I will start by showing the 4 main fuel parameters during startup.
Injector IPW While Cranking Starter:
This is the parameter that squirts the first large burst of fuel to get the engine to initially start. This should only be in effect while the starter signal is being read by the ECU (pin #71 on evo 8's). It also locks the ignition timing to 5* while this wire is engaged. If someone wants to track down the table that locks the timing at 5* during startup, I'd really like to find that since higher timing can make startups faster with big cams.
MAF Scaling Enrichment #1 & #2:
This multiplies the normal High Octane Fuel value to compensate for the colder combustion chamber temps and may not be able to completely ignite the fuel mixture so more fuel is added to ensure the desired amount of fuel actually ignites.
Post-Cranking Enrichment Adder #1 & #2:
This adds a certain amount of fuel to the High Octane Fuel value x MAF Scaling Enrichment. (The High Octane fuel map is actually just a MAF scaling multiplier table. The formula just make it be seen as a more familiar AFR value. Change the scaling from 'AFR' to 'EnrichmentADJ' to see the actual scaling.) We add additional fuel for the first few seconds after the engine initially starts to help stabilize the engines combustion.
Post-Cranking Enrichment Decay:
(I still need to confirm which one is correct with datalogs)
This table determines how long the Post-Cranking Enrichment Adder takes to taper back down to just the High Octane Fuel value x MAF Scaling Enrichment value.
Some of these tables are already defined, I just relabeled their name to be a bit more self-explanatory.
9417:
The ISCV system works in the exact same manner, almost a mirror image. I just need to confirm one or 2 more tables tomorrow before I can make a small write-up for that portion.
If the car won't start at all, even for 1 second, the problem is area #1.
If the car starts and immediately dies, the problem is area #2.
If the car starts, runs for a few more seconds and then dies, the problem is area #3.
-Jamie
I will start by showing the 4 main fuel parameters during startup.
- Injector IPW While Cranking Starter
- MAF Scaling Enrichment
- Post-Cranking Enrichment Adder
- Post-Cranking enrichment Adder Decay
Injector IPW While Cranking Starter:
This is the parameter that squirts the first large burst of fuel to get the engine to initially start. This should only be in effect while the starter signal is being read by the ECU (pin #71 on evo 8's). It also locks the ignition timing to 5* while this wire is engaged. If someone wants to track down the table that locks the timing at 5* during startup, I'd really like to find that since higher timing can make startups faster with big cams.
MAF Scaling Enrichment #1 & #2:
This multiplies the normal High Octane Fuel value to compensate for the colder combustion chamber temps and may not be able to completely ignite the fuel mixture so more fuel is added to ensure the desired amount of fuel actually ignites.
Post-Cranking Enrichment Adder #1 & #2:
This adds a certain amount of fuel to the High Octane Fuel value x MAF Scaling Enrichment. (The High Octane fuel map is actually just a MAF scaling multiplier table. The formula just make it be seen as a more familiar AFR value. Change the scaling from 'AFR' to 'EnrichmentADJ' to see the actual scaling.) We add additional fuel for the first few seconds after the engine initially starts to help stabilize the engines combustion.
Post-Cranking Enrichment Decay:
(I still need to confirm which one is correct with datalogs)
This table determines how long the Post-Cranking Enrichment Adder takes to taper back down to just the High Octane Fuel value x MAF Scaling Enrichment value.
Some of these tables are already defined, I just relabeled their name to be a bit more self-explanatory.
9417:
Code:
<scaling name="PostCrankEnrich" units="ms" toexpr="x*0.024" frexpr="x/0.024" format="%.3f" min="0" max="6.12" inc="0.024" storagetype="uint8" endian="big"/> <table name="Injector IPW while cranking starter (Main Maps)" category="Startup Fuel" address="56ae" type="2D" level="3" scaling="TimeInjCranking"> <table name="Coolant Temperature" address="67bc" type="Y Axis" elements="9" scaling="Temp"/> </table> <table name="Injector IPW while cranking starter (ALT MAPS)" category="Startup Fuel" address="3924c" type="2D" level="2" scaling="TimeInjCranking"> <table name="Coolant Temperature" address="67bc" type="Y Axis" elements="9" scaling="Temp"/> </table> <table name="MAF Scaling Multiplier vs Coolant Temp #1" category="Startup Fuel" address="3722" type="2D" level="1" scaling="EnrichmentAdj"> <table name="Coolant Temp" address="67bc" type="Y Axis" elements="9" scaling="Temp"/> </table> <table name="MAF Scaling Multiplier vs Coolant Temp #2" category="Startup Fuel" address="3712" type="2D" level="1" scaling="EnrichmentAdj"> <table name="Coolant Temp" address="67bc" type="Y Axis" elements="9" scaling="Temp"/> </table> <table name="Post-Cranking Enrichment #1" category="Startup Fuel" address="3732" type="2D" level="1" scaling="PostCrankEnrich"> <table name="Engine Temp" address="67bc" type="Y Axis" elements="9" scaling="Temp"/> </table> <table name="Post-Cranking Enrichment #2" category="Startup Fuel" address="3742" type="2D" level="1" scaling="PostCrankEnrich"> <table name="Engine Temp" address="67bc" type="Y Axis" elements="9" scaling="Temp"/> </table>
If the car won't start at all, even for 1 second, the problem is area #1.
If the car starts and immediately dies, the problem is area #2.
If the car starts, runs for a few more seconds and then dies, the problem is area #3.
-Jamie
Last edited by Dynotech Tuning; Jan 22, 2013 at 07:05 AM.
Would be nice to have a parameter tied to the factory sas routine. But..either ac switch since I don't have an ac unit or rpm based . Generally speaking 3000 rpm will be the lower bounds of my als set up . So the demand adder for rpm could work just as well. You would have to engine brake the rpm below 3000 to get normal idle which is fine for me.
Is the table with demand vs cts that correlates to ac on drive a table that used for ac on vs cts? 8858 is still primitive for idle development. These tables hopefully get a correct name soon. Ac sw on vs cts demand ac off vs cts demand etc
Is the table with demand vs cts that correlates to ac on drive a table that used for ac on vs cts? 8858 is still primitive for idle development. These tables hopefully get a correct name soon. Ac sw on vs cts demand ac off vs cts demand etc
Last edited by 211Ratsbud; Jan 22, 2013 at 06:25 AM.
Perfect timing Jamie,
Was rough this morning, tomorrow s/b 10-15 degrees tomorrow AM
Wife,
what's wrong with your car, why doesn't it start, why don't you get a regular car, blah, bah, blah, yeah, yeah, yeah
Was rough this morning, tomorrow s/b 10-15 degrees tomorrow AM
Wife,
what's wrong with your car, why doesn't it start, why don't you get a regular car, blah, bah, blah, yeah, yeah, yeah