85 Firebird GenV swap

[KLUMINATI]

I have a Gen V lt1 swapped Firebird. When it idles it sounds great. Battery died so I jumped it and when it revs it hangs around 3k for a bit. No matter how light I hit the throttle..

Also seperate issue it has a whine as RPMs fmgrow but at idle I hear a chatter wondering if that could be my torque converter.

Again it's to seperate issues I'm trying to address, a rev hang no matter the amping of throttle given and chatter inside trans at idle but you can feel it at belonging sounds like something making contact with something when pulled I see no evidence of it.

[RC2]

What transmission and converter are in it? My 6L80E with a triple disc FTI sounds the same as what you're describing.

[KLUMINATI]

What transmission and converter are in it? My 6L80E with a triple disc FTI sounds the same as what you're describing.

It has an 8l90 with a stock converter..
I'm assuming it may be the converter as the noise comes from the bellhousing location and the whine under acceleration as well. I'm gonna double check the fluids topped off. Cause I could be not accommodating the correct amount for the cooler to fill as well. But I'm sure 10qts should still be enough to see movement.

So I'll report back anything I find before I possibly swap in my other torque converter.

[KLUMINATI]

Also anyone please excuse the typos in the initial context. I didn't see them til now. I understand how it can gather a lack of replies.

[ns158sl]

pretty hard to help without a toon and a log? Assuming a bone stock LT1 maybe with headers?

[edcmat-l1]

Nobody can tell anything without looking at a data log and tune file.

"My car does this ____" what can it be???

10 qts. is not enough to fill that transmission.

[KLUMINATI]

Nobody can tell anything without looking at a data log and tune file.

"My car does this ____" what can it be???

10 qts. is not enough to fill that transmission.

What would my log tell you about the transmissions issue with chatter? I get you guys love to get the most info for answering questions. But my tune won't tell you why there is chatter at the flexplate/TC. Would it?

As for the rev hang I actually realized the issue and I did a throttle body clean it went away. So I'm sorry I didn't upload my log or tune as I don't see a chatter noise being caused through the tune as the engine ran fine without the transmission attached and has no issues. So rather then awaiting the "Whats wrong with my car" answer I was diagnosing it myself as well.

I do appreciate that you said 10qts isn't enough to fill the transmission.

As for the chatter I already pulled the starter to inspect so I will update anything I find for anyone that faces the issue. I have a spare TC to install if need be.

Should anything arise I will be sure to add my tune to any future replies as I understand you guys surely may know more than me when looking at it. Thank you again for the replies.

[edcmat-l1]

What would my log tell you about the transmissions issue with chatter?
Should anything arise I will be sure to add my tune to any future replies as I understand you guys surely may know more than me when looking at it. Thank you again for the replies.

That's exactly why you should post a tune file and data log. There are people on here who can look at the same screen you're looking at and know far more than you about what's going on.

[96GS007]

Throttle hang alone is enough of a reason to post the tune and log.

Lots of really smart folks on here. Help them help you.

[KLUMINATI]

Bringing this thread back to life,

Throttle hang issue had subsided or it stopped doing it for its own reasons, Still trying to figure out if the chatter I hear in bell housing is the Torque converter.
I pulled the Torque converter mounting bolts and ran the engine free of it - No noise.
I reattached the torque converter and it seems to have obviously began again, used a borescope and i see no play or movement. So maybe its internal torque converter failure?

Also I noticed the engine has negative Trans Engine Torque when its sitting @idle, Is it possible the trans doesn't have any/or enough line pressure?
I did try and get it rolling by pressing attempting to power brake and it didnt seem to even begin to budge @ maybe 10-15% throttle.

Heres log and tune file info:

[KLUMINATI]

Also I notice my trans temp on PIDS has never went up. just danced between a degrees up or down or stayed idle. Sounds like no flow

[KLUMINATI]

Decided to run the motor again, noticed less noise in the bellhousing on start up but that doesn't mean the flywheel isn't cracked, Decided put it in reverse noticed it didn't roll forward like it does when I releasing brake with the car off and have it in neutral to get a bit of space behind it from garage wall. So thinking it was a good sign I decided to do a light bit of throttle and it just runs to about 3k and then rev hangs for a good 5-7 seconds which i already have it in neutral so it doesnt do more damage then good. Comes down and when I go back up through reverse it revs itself like it attempts to rev hang again from the obvious more rpm that gets adjusted in for going into reverse but excessive and before it can do that i get it into park and it readjusts and i turn it off..

Now I have no alternator charging as i believe it needs to be grounded but the wire that goes back to PCM is connected. But regardless of that information otherwise car fires up fine.. Why would I be having a rev hanging issue? It did all though make me realize the trans whines like a whench from the salty seas of the eyer as its rev hanging, so it needs fluid but id love to fix the throttle issue to be able to get it warmed up enough to add the proper amount of fluid..

Any direction or help is greatly appreciated. My last log and tune filelog625.hptlastlog.hpl

[relicdew]

Is your engine stock or modified? The computer is programmed for a L86/8L90 but the cylinder volume was changed to a 5.3 variant. There appears to be a lot of changes made to this tune that make zero sense. Where are people getting this stuff from?

Your computer is based off a L86 engine and 8L90. Somebody compared a 2017 L83 truck file and hit copy/paste on everything and then started adjusting other parameters. NOT the way to do this folks. That's your issue, get the correct computer with the base tune that matches your engine/transmission combination or simply make smaller changes to the base file instead of copying/pasting the entire tune over. Your likely not going to fix this until you start back over with the correct base file or have the OEM tune to compare to and put everything back to stock and make small changes. I see this a lot from harness companies selling folks computers and they don't have the correct means to change the tune over to match the customer's setup or the end-user would need a different compatible computer to match the engine/transmission combination.

[KLUMINATI]

Is your engine stock or modified? The computer is programmed for a L86/8L90 but the cylinder volume was changed to a 5.3 variant. There appears to be a lot of changes made to this tune that make zero sense. Where are people getting this stuff from?

Your computer is based off a L86 engine and 8L90. Somebody compared a 2017 L83 truck file and hit copy/paste on everything and then started adjusting other parameters. NOT the way to do this folks. That's your issue, get the correct computer with the base tune that matches your engine/transmission combination or simply make smaller changes to the base file instead of copying/pasting the entire tune over. Your likely not going to fix this until you start back over with the correct base file or have the OEM tune to compare to and put everything back to stock and make small changes. I see this a lot from harness companies selling folks computers and they don't have the correct means to change the tune over to match the customer's setup or the end-user would need a different compatible computer to match the engine/transmission combination.

So I asked one other who said tune, started comparing mine to a base tune from a truck that i had logged and read the tune from..
Noticed how much of a difference there was, called PSI cause they sold me the harness and computer, Got a base tune file compared that as well to the "tuners" file.
Noticed how off that was. Gonna write the base tune back into the computer and run it see how things look. I rather either learn to do this myself or at the least what im truly looking at going forward.
Thats 4-500$ for something thats withheld this build for months cause I assumed possible throttle issues and so forth.

[KLUMINATI]

Ok i uploaded what was supposed to be a base Gen V lt, I will attach at the end.
I ran the car on the tune didnt get a log cause all though it was running it was holding an idle at 1200
While commanded idle @ the time was in 800's. This tune makes it run worse basically
I gotta admit, I think I am at the point of maybe just study and make my own base tune? I already have the logs and info. (rambling to self)

[KLUMINATI]

Base GenV LT street tune.hpt

[KLUMINATI]

Well I figured out the rev hang, tune was never an issue..
Rechecked some old logs from the initial day tune was put in.
ran beautifully, noticed it seems to be losing air, phukn vacuum leak.

Other than fixing that, gonna move on to Transmission diag. Time to get this thing finished.

[greezemonkey]

might be the idler off the stator looks to be on the 8 speeds and 10 speeds https://www.youtube.com/shorts/zk-Snj-pqic