Fourth gear lugging

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Mar 5, 2019 | 11:07 AM

qweedqwag

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Fourth gear lugging

So in fourth gear while crusing around 50-55 mph around 1800 rpm, the trans seems to be lugging, is this from the 3600 stall in the car? Why does it happen if it is?

Mike.

Mar 5, 2019 | 11:10 AM

MaroonMonsterLS1

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From: Iowa

is the converter locking? You will feel another 200-300 rpm drop when converter locks.

Is that what you're feeling?

Mar 5, 2019 | 11:15 AM

qweedqwag

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ItvIt d drop like you said but starts to kinda lug like it's going in and out of gear, even though it isn't, just feels like it not good for the trans, it only does this in fourth gear just sound and feels weird.

Mar 5, 2019 | 12:29 PM

MaroonMonsterLS1

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Maybe a video...a mention of codes...a data log...line pressure test

Nobody here is doing a ride along, so you either need to be specific as all hell, or provide more info

Mar 5, 2019 | 03:41 PM

98CayenneT/A

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Converter is locking up at to low rpm. Next time it does it keep your foot on the gas and lightly press the brake. That will unlock the converter and im guessing it will go away

Mar 5, 2019 | 03:57 PM

qweedqwag

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Quote:

Originally Posted by 98CayenneT/A

Converter is locking up at to low rpm. Next time it does it keep your foot on the gas and lightly press the brake. That will unlock the converter and im guessing it will go away

Your a smart cookie, that's what I though it might be, and it does stop if I put my foot on the brake but. it comes back, is there any way I can change lockup in HP tuner, it's one thing I haven't tried yet.

Thanks 98.

Mike

Mar 5, 2019 | 04:28 PM

mrvedit

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Yes, the lockup speed can be changed in HP Tuners. Try setting it 5 mph higher.
Does your engine have a hot cam in it? Modified engines often need a higher lockup speed to prevent that "surging" feeling.

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Mar 5, 2019 | 10:22 PM

qweedqwag

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Can anyone look at my toon file and look at the lockup in fourth it seems like its locking up around 80 mph but im no sure.
And yes my cam is big 242/248 110 lsa
Mike

Attached Files

Bird Original tune.hpt (219.8 KB, 27 views)

Last edited by qweedqwag; Mar 5, 2019 at 10:35 PM.

Mar 5, 2019 | 10:55 PM

#10

MaroonMonsterLS1

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Looking at the tune, 4th gear lockup is commanded as early as 52mph depending on your throttle input.

I see your current tune shows tire size is 25.7 and gear ratio is 3.42
Is this accurate to your current setup?

What converter do you have? I see its a 3600 stall but who made it and which series?

Mar 6, 2019 | 07:16 AM

#11

tug686spd

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https://ls1tech.com/forums/automatic...tm-w-pics.html

very good thread from the stickies at the top of this forum. Should be able to fix all your problems with this.

Mar 6, 2019 | 08:42 AM

#12

qweedqwag

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Maroon,

Yes that is correct 25.7 and 3.42 I have a Yank 3600ss stall in it .

Thanks sir,

Mar 6, 2019 | 09:30 AM

#13

mrvedit

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From: Ann Arbor, MI

Quote:

Originally Posted by MaroonMonsterLS1

Looking at the tune, 4th gear lockup is commanded as early as 52mph depending on your throttle input.
...

I also looked at the tune and agree.
Something to keep in mind is that the lockup speed at 31% throttle is 75 mph. If your TPS sensor is defective or misadjusted, it could signal the PCM that the throttle is at e.g. 31% when it really is much less.
We could diagnose this better if you posted a log file containing data when you trans locks up at that high speed.

Mar 6, 2019 | 11:50 AM

#14

qweedqwag

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OK I can do a log but what TCC perimeters do I need to log to help you? Do you want to see it in chart vs time or a gauge?

Mike.

Mar 7, 2019 | 07:13 AM

#15

MaroonMonsterLS1

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Tcc (yes/no)
Tcc pwm
tps
mph
rpm
maf
map
solA
solB
gear commanded
gear calculated
spark advance
misfires
if it's new enough to have an input speed sensor...log input speed rpm

Mar 7, 2019 | 08:50 AM

#16

Jays_SSZ28

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Quote:

Originally Posted by qweedqwag

So in fourth gear while crusing around 50-55 mph around 1800 rpm, the trans seems to be lugging, is this from the 3600 stall in the car? Why does it happen if it is?

Mike.

So this car used to run great, no work was done, then just one day this all starts?