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View Full Version : How to fix lean tip in-off idle-stumble like no carb accel pump?


turbovanmanČ
08-30-2009, 03:27 AM
When I hit the gas from an idle, I get a lean flat spot, like having no carb accel pump. Its friggin annoying, it goes it to 20:1, stumbles then its fine, its worse cold but still there warm. Which parameters do I need to tweak?
ShelGame
08-30-2009, 09:29 AM
Sounds like you have the T-SMEC misfire bug - you just don't get a misfire with it, just lean transient.

Why don't you try this:

Find the table called LMAPTC. This is the lookup table for the time-constant that's used to calculate the average MAP that is used in the transient fuel calcs. Technically, this is not a MAP-based table, so it doesn't get scaled for MAP. But, obvioulsy, the number of bits ber PSI changes when you change the MAP sensor. So, this table should get some tweaking.

In the T-SMEC thread, I asked a couple of guys to try this, and it didn't really do much for them IIRC. But, maybe there were other things going on at the same time.

I would start by scaling this table down by 66% on the Y-axis in D-Cal and see if it's any better. I think the table is a constant return. You could also try to add a couple of points, and simply reduce the time constant at the lower temps and see if that helps. But, I'd start simple and see if you can make it better or worse with that table...

EDIT: I also think that table should come into play when you put in a bigger throttle body (which I think you have). This is because as you increase the size of the throttle chamber, the MAP reading will change faster than with a smaller T/C. So, the time constant for the averaging function should be shortened with a bigger T/C. The question is - how much? I really don't have a feel for that...
turbovanmanČ
08-30-2009, 02:02 PM
EDIT: I also think that table should come into play when you put in a bigger throttle body (which I think you have). This is because as you increase the size of the throttle chamber, the MAP reading will change faster than with a smaller T/C. So, the time constant for the averaging function should be shortened with a bigger T/C. The question is - how much? I really don't have a feel for that...

This is exactly what I was thinking, the 58mm flows too much air and I get the stumble.

It could be a misfire but to me, feels like a lean shift. I'll try what you suggested and see what happens.
turbovanmanČ
08-30-2009, 03:46 PM
Ok, its called the "time constant" and I can't adjust it, the tbl file we have doesn't have it activated so to speak. I am using a current TSMEC cal.
ShelGame
08-30-2009, 09:13 PM
Hmm, it should be. What version are you using? v15?

ON a side note, I scaled this table in all of my 'modified' cals. When I realized it wasn't a MAP based table (and that Geoff didn't scale it for Ladybug), I changed it in T-SMEC to unscaled. None of my modifed cals have the lean stumble/misfire thing...
turbovanmanČ
08-31-2009, 01:38 PM
Hmm, it should be. What version are you using? v15?

ON a side note, I scaled this table in all of my 'modified' cals. When I realized it wasn't a MAP based table (and that Geoff didn't scale it for Ladybug), I changed it in T-SMEC to unscaled. None of my modifed cals have the lean stumble/misfire thing...

Its your latest one, I made this one a few weeks ago, its not there, its just childish scribble. :(

So your saying that could be the fix?

I need another tbl file with that in there to adjust it.
ShelGame
08-31-2009, 02:05 PM
Hmm, maybe you swapped over a table file from a different cal? If you get lines all over the place for that table, then that's what happened. It should be a single-point table, I think.

It could be the fix. Like I said, we tried it in the T-SMEC thread, and it didn't fix it. But, there likely were other things going on then, too. I think this table should be scaled with MAP. I'm just not 100% sure it needs to be scale the SAME as MAP. It might need to be a different facto than the MAP scaling. But, I think the same factor as MAP is as good a guess as any...
turbovanmanČ
08-31-2009, 02:16 PM
Ok, can you send me another tbl file.
ShelGame
08-31-2009, 02:37 PM
Send me (or just post) your bin/tbl file, I'll try to find the right address for the LMAPTC table...
turbovanmanČ
08-31-2009, 02:59 PM
Send me (or just post) your bin/tbl file, I'll try to find the right address for the LMAPTC table...

Ok, I'll have to do that tonight, its at home on my thumb drive.

I'll post it here.
SebringLX
08-31-2009, 05:25 PM
I get the same thing when turning right if I have less than half a tank of gas. I know the cause of it is different for me, but it is quite annoying. Also very odd since it only happens when turning right, never when turning left.
turbovanmanČ
08-31-2009, 06:36 PM
I get the same thing when turning right if I have less than half a tank of gas. I know the cause of it is different for me, but it is quite annoying. Also very odd since it only happens when turning right, never when turning left.

So then, you know the solution, don't turn right, :drum:
ShelGame
08-31-2009, 10:29 PM
I'm up for another half hour, if you post those files, I can fix your .tbl and repost it for you...
turbovanmanČ
09-01-2009, 01:34 PM
Ok, I can't attach it here even though its saved to my computer?

Do I have to rezip it?
ShelGame
09-01-2009, 02:46 PM
Ok, I can't attach it here even though its saved to my computer?

Do I have to rezip it?

Yep, zip them up...
turbovanmanČ
09-01-2009, 02:56 PM
Ok, lets try this-
ShelGame
09-01-2009, 03:50 PM
I need the .bin, too. That's just the .tbl file. Send me the files that have the f'd up lines for the LMAPTC table...
turbovanmanČ
09-01-2009, 05:06 PM
I need the .bin, too. That's just the .tbl file. Send me the files that have the f'd up lines for the LMAPTC table...

You want ALL of them? I figure that's at least 6-10.
ShelGame
09-01-2009, 10:25 PM
I just need the .bin and .tbl that you load up that has the messed up LMAPTC. I don't need the T-SMEC build files (the .asm's)...
turbovanmanČ
09-01-2009, 10:35 PM
Ok here's the bin file, I have more but I'll just give you the main one I am using.

Removed, bad fin file.
turbovanmanČ
09-02-2009, 02:05 AM
Sorry Rob, don't use that bin file, I am having a lean issue at 5 inches to 5 psi, I think I fell asleep and changed something. I'll post another one to use.

I also noticed the S60 cal doesn't have this issue, it has a tiny one cold but that's it.

Use this one, its my race cal-
ShelGame
09-02-2009, 07:43 AM
Sorry Rob, don't use that bin file, I am having a lean issue at 5 inches to 5 psi, I think I fell asleep and changed something. I'll post another one to use.

I also noticed the S60 cal doesn't have this issue, it has a tiny one cold but that's it.

Use this one, its my race cal-

The 'TimeConstant' table looks OK on this one. It just needs to be scaled by 66% on the Y-Axis...
turbovanmanČ
09-02-2009, 01:11 PM
The 'TimeConstant' table looks OK on this one. It just needs to be scaled by 66% on the Y-Axis...

Ok, weird, I never checked my race cal as the street cal is simply copied then I rename and change it for pump gas, :confused:

I'll check it in abit.

Don't know what I did, I copied over my settings to a race cal copy and the lean problem has gone away, :confused:
ShelGame
09-02-2009, 03:34 PM
Actually, there are 2 tables that control the MAP averaging time-constant. AETIME (EnrichmentTime_FromTemp) is the other one. Scale the Y axis by 66% on that one, too.
turbovanmanČ
09-02-2009, 04:56 PM
I just looked at both constants and both look like a kid drew them, I'll take some screen shots, I am using D-Cal.

http://i12.photobucket.com/albums/a228/turbovanman/Burner%20chip%20computer%20info%20etc/Timeconstantmap.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Burner%20chip%20computer%20info%20etc/Timeconstantmap1.jpg
ShelGame
09-02-2009, 08:52 PM
I just looked at both constants and both look like a kid drew them, I'll take some screen shots, I am using D-Cal.

http://i12.photobucket.com/albums/a228/turbovanman/Burner%20chip%20computer%20info%20etc/Timeconstantmap.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Burner%20chip%20computer%20info%20etc/Timeconstantmap1.jpg

Send me these files above and I'll take a look. I just need to correct the address for the 2 tables...
turbovanmanČ
09-02-2009, 09:23 PM
You have them, there in the above zip files.

These are what I got the above 2 graph's from.
turbovanmanČ
09-04-2009, 03:43 AM
Any news Rob? I am dying here, literally, :(

When you redo it, how do I fix all my cals and tbl files etc?
risen
09-05-2009, 08:20 PM
Any news Rob? I am dying here, literally, :(

When you redo it, how do I fix all my cals and tbl files etc?

You'll just need to make sure you get the proper address in your .tbl files. If your tables are all different, then you can try to use an offset from the nearest table in the cal(address wise). If the addresses in your other tables are all the same as in the one you sent rob, then you can use the table he sends back.

I'm going to include what you have above as an example in the advanced tutorial video (whenever I get to it).
ShelGame
09-05-2009, 08:59 PM
Sorry man, got busy. I'll look at it tomorrow...
turbovanmanČ
09-05-2009, 09:03 PM
Sorry man, got busy. I'll look at it tomorrow...

That's ok, If I get rear ended, its all your fault, :lol: Kidding, of course. ;)

Its weird, some day's its really bad, others, not so much, :confused:
ShelGame
09-07-2009, 03:02 PM
OK, this is what I get when I load up this .bin and .tbl file. This is what it's supposed to look like. Do you have another file named T-SMECv15.bin in the same folder?
turbovanmanČ
09-07-2009, 05:01 PM
Delete.
turbovanmanČ
09-07-2009, 05:06 PM
OK, this is what I get when I load up this .bin and .tbl file. This is what it's supposed to look like. Do you have another file named T-SMECv15.bin in the same folder?

Yes, I do, I have 2 bin files and 2 tbl files, :confused:

My enrich from time is also messed up.

So which tbl/bin files do I delete?
ShelGame
09-07-2009, 05:24 PM
Which .bin file are you running?
turbovanmanČ
09-07-2009, 09:39 PM
Which .bin file are you running?

Pretty sure the one's I posted here. In the folders, it seems I have Tsmec bin/tbl files and my cal names, IE street cal bin/tbl files?
ShelGame
09-07-2009, 09:56 PM
In the screenshots (dunno why I didn't think to look before), it says the file name is 'GT35R.bin'. Send me those files and I'll fix the LMAPTC address...
turbovanmanČ
09-07-2009, 10:08 PM
In the screenshots (dunno why I didn't think to look before), it says the file name is 'GT35R.bin'. Send me those files and I'll fix the LMAPTC address...

Do you want me to post here or email, if email, need your email.

Then how do I fix all the others cals?

Why can't I delete the double files or rename the Tsmec ones?
ShelGame
09-07-2009, 10:40 PM
Do you want me to post here or email, if email, need your email.

Then how do I fix all the others cals?

Why can't I delete the double files or rename the Tsmec ones?

Just post it here, unles you want to keep it secret. In that case, use roblloyd -at- charter -dot- net

You could delete the other files, if you wanted to. Or rename them...
turbovanmanČ
09-08-2009, 02:43 AM
Just post it here, unles you want to keep it secret. In that case, use roblloyd -at- charter -dot- net

You could delete the other files, if you wanted to. Or rename them...

I tried renaming, didn't work and the TSMEC bin file has a different ID number? :confused:

I sent you the cals thru email.