455GTO

iTrader: (18)

I have a 2002 TransAm and recently swapped to a 4l80e using the Speartech harness. My tuner is unsure of how to get the car to shift on its own. He switched the trans option from manual to 4l80e but it doesnt seem to work for tuning. He thinks he will need to buy a credit from hptuners and download an auto car onto my ecu. Is this the case, or can we just download an auto tune that some one can send me? Not too sure on how to make the car know its an auto now. Thanks!

LSX Power Tuning

iTrader: (4)

It depends on how the harness you have is wired. If it's wired to use a relay and a 4l60 tune then you'll need a 4l60e tune. If it's setup to run like a 4l80 then you'll need to do a segment swap for the 4l80.

455GTO

iTrader: (18)

So the tuner was able to get the trans tuned and it works... Only issue now is a constant idle surge in park and while slowly rolling in D. Once I'm at a dead stop, the surge goes away...

He tried playing with different tables and couldn't quite get rid of it... Is this an IAC issue? Again, its only when rolling or in Park...

Jacktuner

Whats the cam specs?

455GTO

iTrader: (18)

Its the Texas Speed Torquer V2 cam.
232/234 on a 114LSA

Its weird that it only surges and dies when im rolling slowly like up to a stop light or in stop and go traffic... If im dead stopped its fine.

mrvedit

Surging is too fast for IAC correction; the idle ignition compensation should handle it.

As LSX has pointed out in other posts, many tuners run too much ignition advance in the idle advance table. This prevents the idle advance compensation from being able to smooth it out.

There are separate idle ignition tables for Park/Neutral and Drive. Sounds like the Park/Neutral table is off, perhaps with too-high values.

455GTO

iTrader: (18)

So for it to surge when rolling it is most likely a too high of timing issue in the idle advance table? When logging we were seeing the timing drop down to 10* and surge back up and down

Johnv

Is the PCM seeing a VSS speed signal ?
Could be something in the rolling idle tables.

I agree with the above also, the timing value that gives the smoothest idle won't necessarily give the most stable idle.
lower timing and more airflow may work better.

455GTO

iTrader: (18)

Yes, it is seeing the speed for sure. When looking at the tune live, the timing at idle in park goes up and down from 10* to 24* like a roller coaster... Same when its slowly rolling... Should the timing in the 400-1000rpm range be around 10* maybe?

LSX Power Tuning

iTrader: (4)

The timing shouldnt be going up and down like that.

455GTO

iTrader: (18)

Would the cause be too much timing in the low rpms?

LSX Power Tuning

iTrader: (4)

No way to know without seeing log and tune. It could be too much or little, or airflow tables not being right. Thats whats most common but still just a guess without seeing any data.

455GTO

iTrader: (18)

Hey guys, so my trans problems are so intermittent its frustrating... Tuner is first time tuning automatic and what he did was just use the auto tables already in the tune and adjusted those...

There was no "segment swap" done nor did he download an "auto file" to load onto my car... Is this why there are issues? How do you normally change from m6 to auto in the tune? He isnt sure if the problem is just using the auto tables that are built into it... HELP

LSX Power Tuning

iTrader: (4)

I always do segment swap on a 4l80 swap unless its being ran like a 60e then I start with a stock auto tune.

455GTO

iTrader: (18)

This is new to both my tuner and myself... How do you get the 4l80e segment and where in the tune is it downloaded? If I post my tune could you take a look at it and see if its possible? Thanks!

LSX Power Tuning

iTrader: (4)

You can do a 4l80 segment on a 2002 fbody, I have done tons of them. You have to have another tune with the same OS (#12212156) and a 4l80 to compare to in order to do the segment swap. I would also start with an auto tune and then do the segment swap.

455GTO

iTrader: (18)

How does one obtain that tune file?

LSX Power Tuning

iTrader: (4)

You can try here, there are stock files there, atleast the last time I looked there were.
https://ls1tech.com/forums/pcm-diagn...ed-2012-a.html

I dont really use that site since I have stock tunes for almost every stock vehicle just from years of tuning. Dont take this wrong but it kinda seems like who ever is tuning your car may be in over their head. I could be wrong but thats the impression I am getting reading your post.

2xLS1

iTrader: (25)

That's being kind.

455GTO

iTrader: (18)

Thanks so much for all your help! And yes, my tuner is a buddy who has only tuned 6 speed cars and just does it on the side... So its a learning process