V6 Bird

iTrader: (15)

I have a Yank TP4000. It shudders when locking up and sometimes slips if i dont let off the gas to let it lock up. What are some things that i can do in Edit to fix this problem.

I know someone had recalibrated their PCM Tranny tables in Edit that is real close with Mike at Yank. Please chime in and give advice or maybe i can get a copy of your exact tranny settings in Edit. TIA.

Mike

Lady Redhawk

iTrader: (6)

Under Engine Diagnostic, the Test Parameters tap. I had to change all the low and medium MisFire Detection tables to 32767. The high stall torque conveter was giving false misfire and that efects the lock and unlock of the converter. This fixed it for me. I

jimmyblue

iTrader: (11)

Is this misfire detection generally the cause
of converter "shudder"? I guess I'm curious
about whether TC lock from high slip causes
true misfires, or false detect of misfire, and
whether there's any way for people without Edit
to suppress this action.

V6 Bird

iTrader: (15)

My car doesnt have a cam so it shouldnt be throwing any misfires....I think Ragtop 99 or whatever his name was had a good solution and it was working well for him....Id like to see his tables if we would reply back <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

TIA

Lady Redhawk

iTrader: (6)

According to Mike at Yank, it is false misfire the pcm is picking up because of the smaller size of the high stall torque converter. Has nothing to do with cam or real misfire. This was the main reason I got LS1edit, to fix my Yank 3300 High stall torque converter. And it has done that.

I also have a tcc table that has worked well for me and others. I can email it to anyone who wants it.

<small>[ April 01, 2003, 10:24 PM: Message edited by: Lady Redhawk ]</small>

jimmyblue

iTrader: (11)

I don't know that a cam has to do with the
misfires. Hopefully someone in the know will
chime in.

How I imagine it goes, is something like this -
going along, all happy, converter slipping at
maybe 500-1000RPM below synchronous and having
the spark advance to match. Now you apply the
lockup clutch and instantaneously raise the load
and cut the RPM. With the original spark, now
maybe you're "over the top" and into preignition
or misfire territory. I doubt the computer is
able to react or predict quickly enough, but it's
able to throw a bitch fit after the fact. So it
goes and tells the lockup to quit, then it's
still time to lock up so it tries again....

With enough misfire counts you could just ride
out the time until the spark gets back to where
it makes sense for locked up. If you had less
timing, maybe you wouldn't misfire. But that's
no fun.

Does this seem like the operating scenario?

Ragtop 99

iTrader: (7)

To solve this it helps to have ATAP.
First make sure your cruise LTRIMs are negative. If not get them negative by tweaking either the MAF table or injector table.

Hook up ATAP and have a guage with TPS showing and go for a drive on the highway. Experiment at various speeds and amount of throttle used until you have a good idea of when the shudder occurs (by mph and TPS). Once you have that you can change the lock-up table so that the converter is unlocked at those areas.

Frequently the shudder occurs at lower speeds and higher TPS levels (e.g. 40 mph with 35% TPS). For my style of driving, I found that the car felt much better by having it downshift to 3rd in those situations rather than just unlocking the converter.

BTW, if you haven't raised your part throttle shift points with a 4400 (or other real high stall), do so. It helps tighten up the converter by using the gears to provide torque rather than the converter. This something else you can play with, but try the following accross the board changes to start (0% TPS - 70%):

1-2 +2 mph
2-3 +3
3-4 +4

2-1 +1
3-2 +2
4-3 +3

Which gears you have will effect what changes you ultimately make. At various points in the table, primarily below 37% TPS, I have even bigger mph changes.

V6 Bird

iTrader: (15)

Ragtop,

Would you mind sending me the file from your tranny settings. Im having the same issues as you are trying to help me fix. I would greatly appreciate if you dont mind...TIA

GrannySShifting

iTrader: (10)

Ragtop's settings are built around 3.73 gears, a 3800 lb car, and having a 232/236 cam. Try doing what he said. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

<small>[ April 03, 2003, 10:32 AM: Message edited by: GrannySShifting ]</small>

V6 Bird

iTrader: (15)

My 9" has 3.70's and i have a pretty decent size cam in as well now as of yesterday. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />