Charlie_B

iTrader: (1)

This may be a dumb question... But what conditions are met when the ECU uses the drive tables, and which are met when the ECU uses the nuetral tables?

Basically, when cruising to a stop, and the clutch is pushed, is the ECU referring to the "Drive" tables? What if I pulled it out of gear? Is it then using the "Nuetral" tables?

Im tinkering with my initial ISCV tables, and am having problems figuring out which one to modify (drive vs nuetral). When I hit the clutch it is stalling, most of the time dying. Would the drive or nueutral table be the one I need to focus on? Without making my topic too OT, am I messing with the correct settings?

BTW: Ive set my BISS to 850-900, desired idle rpm to 1000 (realy not sure if I should be looking at nuetral or drive rpm), scaled maf (still working on it). Relevant mods are ETS intake, open filter, 9653006 ROM in place of 0011 rom.

jmelocik

iTrader: (153)

My understanding is if the vehicle is in motion it is using the "drive" table, if the there is no registered vehicle speed at the ECU it is using the "neutral" table. Probably should ask mrfred or one of the other ECU gurus though just to make sure.

Josh

Charlie_B

iTrader: (1)

no offense melocik, but can any of you other guys chime in with a confirmation of the above post?

I just want to make sure I have it right in my head, even though my two tables are nearly the same now...

Thanks

jmelocik

iTrader: (153)

None taken, I would do the same thing.

Josh

TouringBubble

iTrader: (2)

I've heard the above, but also that the drive tables were for auto transmissions. the only data I've heard to back up any of it was that there was a loggable flag that changed as soon as the vehicle was in motion and that value was tied to the ISCV/Idle tables. This leads me to agree that the drive table is used when the vehicle is in motion.

Charlie_B

iTrader: (1)

TB,
I read an older post of yours last night about tuning the initial ISCV tables by comparing the log values to the map values. Can you explain your process a little bit? Do you basically just give the ECU what it wants per the logs? Sort of like intial timing tuning w/ knock? At what point do you KNOW there is something mechanically wrong?

TouringBubble

iTrader: (2)

most of the time the logged ISCV references the right column of the 3D stepper table. However, tuning the desired ISCV tables will affect the idle as expected ... neutral, drive and AC work as expected as well. Lower the value, the idle drops ... raise it and it rises. the ECU will correct eventually if the values are a little off. I haven't found out exactly how to log the stepper + ISCV or however they work together. It's still a little vague to me.

Generally, idle is too low so the ISCV tables need to be increased. If idle is WAY off, bump the values (neutral, drive or AC respectively) by about 5 increments. Once it's close, bump only by 1 or 2 increments. If you adjust too high the idle will hang above desired or even bounce a few hundred RPM as the ECU tries to correct it down.

All of this rides on the desired idle neutral value as well. The '05 and '06 ECU doesn't seem to reference the desired idle drive or AC values as defined in ECUFlash and constantly aims for the desired idle neutral value no matter the n/d/a state. the '03/'04 may be different ... simply log and check. So set the idle neutral value before adjusting ISCV.

Whatever issue you're diagnosing will determine if the issue is mechanical. If the TB is stock and the ISCV isn't gunked up, chances are you can tune the issue out. If the issue is severe and intermittent it might be a mechanical issue (had this recently). Apparently you can use EvoScan in SAS mode to verify/tune the BISS setting, but I'm not familiar with that method. I'm sure there is a write up here somewhere though.

Charlie_B

iTrader: (1)

Thanks for the response. Good info.

You say the logged ISCV value should match the right column in the 3d stepper table. The Y axis (up and down) only goes to a little above 1k rpm, correct? So what portion of the logs do you look at, below 1k rpm? Not when you push in the clutch (>2.5k)?

To note, I did go back to my modified stepper table to get rid of the throttle hang, it worked, and had no effect on the stalling issue. How does that play into this?

TouringBubble

iTrader: (2)

I wish I could tell you. I'm not sure how the scaling was determined for the stepper map. It's definitely got to do with temp somewhere as it's obvious when the modified maps idle bad in cold weather. I don't have my modified scaling in front of me, but the Y is scaled to Load instead of temp. I'm not sure thats right, but the disasm guys said it was.

Charlie_B

iTrader: (1)

TB,
When you get a chance...Would you mind giving me some more info on your stepper table scaling? Id like the numbers to at least make some sense, before I start messing with them.

TouringBubble

iTrader: (2)

Even the revised scaling doesn't make sense to me ...



The issue is that both the load and temp scaling suggested in the stepper table thread (and shown here) are completely different from any other reference to load or temp. That's why I don't get it. Also, changes to only the right column of the table (i.e. EvoKids map) can cause issues with cold starts, which doesn't follow the idea of temp scaling on the X.

However, I know nothing if disasm or how these scalings were decided upon and those in the know could possibly shed some light.

jebjkey

iTrader: (1)

looing for info on the iscv tables as well. i think there are some other threads that go into detail on the iscv table. maybe i will search for them