I cannot seem to find any explanation on the following contants/table values for the torque converter (except the temp & mph lock/unlock values) and "Decel Enlean". None of the values have been changed from the stock bbzb code. I'm having some drivability issues with the TCC lockup and when coasting. For you PROM burning gurus, would you mind either explaining what some of these values are or share what's in your tables compared to the stock bbzb values I'm using, which don't work!!! Here are the TCC Constants:

When letting off the gas from running the engine at ~2000 rpms or higher at a constant speed to slow down (coast), the engine rpms hunt from around 1000 to 1500 rpm. I'm thinking this has something to do with these table values:

Can you be more specific?.

Is there a "manual" decribing what all these constants and tables are? Based on the fact that I don't have one (if one exists), I'd like to know what is:

TCC Coast Load Limits Hysteresis
TCC Coast Load Limit (Low mph)
TCC Coast Load Limit (Hi mph)
TCC Negative Delta TPS Unlock Limit
TCC Positive Delta TPS Unlock Limit

and

Decel Enlean Coolant Factor vs. Coolant Temp
Decel Enlean MAP Contribution vs. Delta MAP
Decel Enlean TPS Contribution vs. Delta TPS
Decel Enleanment Multiplier vs. MAP

and in TunerPro, what is

DFCO rpm Enable Threshholds?

OR to make this whole thing simple, do the stock bbzb values as I've shown above look within reason for proper TCC operation and deceleration?

I don't use a auto so I would have ignored that section, but how about the turbo-p4-doc ??

http://members.cisdi.com/~anesthes/p...prom/749/docs/

^^^

--- Joe

Wille, I compared my stuff with what you have and its exactly the same except I have a bigger split in mph for tcc lock & unlock, I did this so the tcc wouldn't be as busy-cable driven speedo in cold temps tends to make vss surge thus making tcc very busy with small split in mph.

I wouln't think its a tcc issue, tcc unlocks every time you let off the gas (at least in my car it does), my first impression was a slow IAC, I've seen slow IAC motors cause big idle changes since they respond a week later than the ecm tells it to so the idle is then too high or too low so the ecm sends another big change. So now its idling high then low then high then low. So I would check or replace the IAC if you suspect it could be a problem & I would only recommend an A/C Delco brand.

How about blower surge? Is it maybe time for a BOV?

I also have an Aqua mist 2d system which has a great feature. I have an in car led display of my injector pulse width. Its a simple green led light that pulses. The best part I like is when I'm in DFCO I actually see it occur. When I drive and reach the correct parameter for DFCO the led goes out & rpm drops, sometimes I'll let it run in DFCO mode until it runs out of DFCO mode & I'll see the pulse width start back up again, right around 1000 rpm and the vehicle speed set up in the chip, somewhere around 25 mph, I'd have to double check, I do get a little rise in rpm, but it comes right back down-function of IAC. Its kind of fun to watch. DFCO I have found is not a given-meaning it doesn't always occur, you have to be within the parameters, it doesn't happen every time you let off. So if your problem happens every time, I wouldn't blame DFCO.

Joe, I looked at the Turbo P4 document. There is a write-up on the Decel Enlean. I'll have to study this. As far as the TCC is concerned, there is no info. But I did play with most of these constants while plugged into the Romulator. I did not know what the TCC Load Limit Hysteresis was, so I increased its value from 2 percent to 30 percent. I discovered that this allows the converter to stay locked longer after lifting on the gas pedal. It eventually unlocks as the car slows down. Allowing the converter to stay locked under deceleration (initially only), the rpm's do not hunt. Once the converter unlocks, the engine returns to around 1000 rpms, then down to my idle, which is 850.


Wille, I compared my stuff with what you have and its exactly the same except I have a bigger split in mph for tcc lock & unlock, I did this so the tcc wouldn't be as busy-cable driven speedo in cold temps tends to make vss surge thus making tcc very busy with small split in mph.

Kevin, I noticed my narrow spread too. I retained my 40.9 mph lockup but lowered my unlock point to 37 mph. It helped keeping the lockup from engaging/disengaging constantly.


I wouln't think its a tcc issue, tcc unlocks every time you let off the gas (at least in my car it does)....

I'm beginning to wonder if this is proper operation under all conditions, etc... As above, if you increase the hysteresis, you can adjust the amount of time the converter stays locked after lifting.


....my first impression was a slow IAC....

I thought of this too... I'm still playing with the VE tables and had another thought. Maybe the 20 kPa column's values are causing the engine under deceleration to run very lean, causing the hunting???? I may be totally wrong here though....


How about blower surge? Is it maybe time for a BOV?

Well...... it's not. I don't have the turbos installed yet!! Once I resolve my VE tables, then figure out PE, I'll be ready.

I have an in car led display of my injector pulse width. Its a simple green led light that pulses.

Cool. I bought a "kit" from an Australian company that converts the injector pulses to an LED digital display (from 00 to 99 percent). I haven't installed it yet though..


The best part I like is when I'm in DFCO I actually see it occur.

Fill me in!! What is DFCO??????

Willie

Decel fuel cut off.

Some bins have a flag to set for stay locked in DFCO.

$58 has closed throttle tables.

You might want to try out the $58_rr_V14.ecu at moates.net.
It has more decriptive labels for things.
Just import the ecu and save it as an xdf.

Thanks Z69. I've been using V12. Didn't know there was a V14.

On the DFCO, what values should be used? I'm using 1100 / 1600 rpm, which is the stock bbzb settings.

Willie

I had a similar problem and I got it alot better ( cant remember how good, bben a while since I drove the car..) after I had been tweaking the Ve tables in the low kPa areas AND Closed Throttle tables (SA and VE)

/N.