Few questions on my 1st LT1 tune

[JustinSEO]

I have started my first LT1 tune; downloaded my stock bin the other day, and have been slowly reading into and modifying small stuff like fans, did the BLM PE WOT patch etc;

I had a few questions about my stock bin; It had a 0 for the Injector Flow, Cylinder Volume, and the speedometer seemed to be way way off from the spreadsheet's calculations.... is this normal? I noticed so many things were way different with the 95 z28 stock bin compared to my car (other then the trans stuff, I know they are way different anyway).

Secondly, I was wondering about tuning for CAI; Cat-Back; 3500 Stall + Shift Kit.... I will change PE WOT AFR once my wideband comes in, and add a couple degrees of timing throughout but the big question I have is tuning for the stall and shift kit.... I have only had the car for a few weeks but it definitely slaps the rev limiter leaving first, and I got damn close in second even with letting out. I have changed shift points, but I have read so many opinions about changing line pressure when you already have a shift kit; The trans has only 7,000 miles on it since the build, I really do not want it to shift "harder" but faster.. What should I look into to shorten time between shifts?

Also, which values need to modified for a stall that big? Can I up my main line pressure to help the stall? What about TCC I have no experience with Automatics so I am completely lost there.

Sorry for all the q's hope I can get some help.... I am worried about flashing this bin before I get an answer about those 0's.

My edited bin is here > http://www.gearhead-efi.com/Fuel-Injection/attachment.php?attachmentid=7637&d=1408227723
My stock 1994 Camaro Z28 A4 Bin is attached below, for anyone who may want to look at it for me or need it!

[steveo]

I had a few questions about my stock bin; It had a 0 for the Injector Flow, Cylinder Volume, and the speedometer seemed to be way way off from the spreadsheet's calculations.... is this normal? I noticed so many things were way different with the 95 z28 stock bin compared to my car (other then the trans stuff, I know they are way different anyway).

that would likely be the EEB revision. best to start with a stock EE bin and flash that so everything works like planned, or use tunercat's EEB definition (there's no tunerpro EEB definition afaik)

[JustinSEO]

I don't have a stock EE bin though, I only have my bin; I've not been able to find another 94 z28 A4 bin anywhere...

So you say i should flash with a new bin other then my stock one edited?

[steveo]

well, you certainly can't edit your existing bin with tunerpro... unless someone writes a proper EEB definition for it. if you want to use your existing bin you'd have to use tunercat with his EEB definition.

[JustinSEO]

Well I bricked my PCM good thing I bought a spare before all this... I did a EE flash and went for a drive, the speedo was maxing out and hence the values were different from my EEB bin I plugged them in there and attempted another flash, as soon as it finished I turned car off for 30 seconds then key back on and fans kicked in full speed without a high temp I knew right off... It would crank and idle but not take any gas. Now I'm gonna have to tune around DTC 83 and edit everything I can tell shift points are way different. My converter locks up ok and it's running but BLM were down around 112-115 on decel and below 128 on WOT


don't think I'll reflash until I can send my spare one out to be repaired, I daily this car.

[steveo]

blms always show a bit low in cell 17 (decel), 'specially on a modified LT1, that's alright.

in EE, the trims should never be below 128 in power enrichment mode (WOT) .... unless you run a vette bin which i think will hold those trims down to 120 but im not 100% on that.

[JustinSEO]

I will have to watch my data log again and verify, but I can definitely tell that there is something going on with that 95 z28 flash... The PCM was a Cardone Reman unit, unsure of what all they do with them. I had to move my knock module over, and then i read the PCM to check it out and make sure it was populated with data and then i data logged on first fire up... It'll run just doesn't perform like my old tune did.

[lionelhutz]

Why not grab any 94 auto bin and basically copy everything that is different from your original bin over to it? Well, only copy the parts that are correct from the EEB bin.

I wouldn't try switching a manual bin to an auto bin using the auto/manual flag, I recall there was a question of that flag being correct that was not fixed.

Also, be careful of the transmission pressure scalar. Raising the max pressure scalar does not increase the line pressure. Read the comments from sherlock9c1 on the transmission line pressure here.

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3566-LT1-8051-tip-in-lean-Anybody-had-success-curing-it

[steveo]

I wouldn't try switching a manual bin to an auto bin using the auto/manual flag, I recall there was a question of that flag being correct that was not fixed.

that has been fixed and verified working in the latest revision of EEX on either my site (resfilter.net) or the sticky thread on this site.

i took my manual bin, switched the flag, sent it to an auto guy, it's been workin' fine.

[lionelhutz]

Good to hear, I was thinking the bit for that flag wasn't known.

In that case any 94 bin would work as a starting point.

[JustinSEO]

I would like to get a 94 a4 bin and flash it I just don't need another bricked pcm. I was thinking of getting another locally for 60$ and trying to flash it.. My car is running for now and it has to run because it's a daily.. I just hope I'm not doing any damage with a 95 vert pcm and flash in my 94..

Definitely gonna read up more on the dos and donts. I have EEx and I will be using it to edit a stock 94 EE bin if I can find one anywhere.... I haven't seen one online that still works.

[lionelhutz]

I'm not sure what you did during programming to brick your PCM, but you should be able to flash any $EE bin into it without issue.

There is a 94 T/A bin on the site you could start with.

[steveo]

sometimes flash memory just dies. it's not super awesome flash memory

definitely get a spare ecm

but keep in mind i flashed mine at least 1000 times, and before i had it, it was an exchange ecm from a tuning shop so godknows how many times it'd been flashed before.

[JustinSEO]

Gosh, my current tune is trash compared to my old one.... The car is running higher RPM maybe from the TCC problems; The speedo is way off, the BLMs are all over....

Someone link me to a stock 94 bin? I have been looking for one....

Here is a copy of my datalog, if you wish to take a look plz do; seems like the car is running kind of rough.

[sherlock9c1]

I can lend a bit of advice on transmission tuning as I have had LT1/4L60Es for a long time.

1. The 4L60E has no built-in pressure sensor to provide feedback to the PCM, so all it can do is gauge shifts based on time. Just like you bought a wideband, buy a transmission pressure gauge and drive around for a few weeks with the gauge strapped to your windshield wiper like a hood tach so you can get an idea of what it's really doing pressure-wise. Ebay seller cmbclalb sells a good one that I've used for a long time. A healthy 4L60E will have around 70psi at idle in Park, Neutral or Drive, and climb to around 150psi in reverse. You should see over 200psi at WOT at some point in 1st gear.
2. Think of line pressure tuning as two separate regions; during shifts, and between shifts. If the trans is not slipping in gear, then leave the line pressure tables alone and ONLY reduce the "Shift time (sec) vs. TPS vs. shift." In the last LT1/4L60E I tuned, the WOT shifts were perfect at 0.600 sec for 1-2 and 0.875 sec for 2-3. Leave the 3-4 shift at 0.00 seconds because the 4th gear apply piston is small and needs no softening. That 1-2 shift value gave me just a slight chirp from the rear tires. I tried 0.400 sec but it was too harsh and barked the tires. 0.800 sec wasn't firm enough and was actually cutting pressure during the shift according to Datamaster.
3. The 4L60E is a bit of a hybrid transmission in that the shift solenoids command the START of the shifts, but the actual shifting is still completed by hydraulic valves, unlike something like the Chrysler 41TE where the solenoids directly fill the hydraulic circuits with no additional valves. Sometimes these shifts take a long time to complete, so if you're hitting the rev limiter and you have sufficient line pressure during the shifts, you need to reduce the shift MPH to get the shift to complete on time. A looser converter, numerically lower rear axle, more engine torque, and more vehicle weight will all exacerbate this late shift behavior.
4. Shifting harder IS shifting faster, and vice versa. It's really a balance point. For modded vehicles, the only way to get your 4L60E shifting perfect assuming it's in good mechanical health is to dial it in over the course of a datalogging/tuning session, or in my case, a road trip.
5. No need to up line pressure with a looser converter unless you think it's slipping. The easiest way to do this is to reduce the "maximum line pressure" scalar 5-10% which will give you 5-10% more pressure across the board at part throttle, but it will NOT give you any more at WOT once the sum of the line pressure tables equals or exceeds the scalar.

[kur4o]

You can try this bin.
It`s 94 a4, 3.23 gears, stock file.
Cal id is 16210011 wich is the latest update fix for your vin

Your stock bin information
Vin 2G1FP22P4R2121999
CAL id 16199611

Check yourself here:

https://tis2web.service.gm.com/tis2web

[JustinSEO]

Can I open two tuner pro and copy values from my old EEB 94 bin into my 95 pcm and flash them to it? Use difference tool to see what needs to change and simply change them all?

[lionelhutz]

You can use the difference tool but you have to make sure you don't copy the data that is mapped wrong and is bad.

I'm not sure why you're stuck on a 95 bin. The PCM doesn't care which year of bin you use and there was a 94 bin posted for you.

[JustinSEO]

I'm not stuck on it just sketched out because of that checksum error I seen before; I believe that is what caused all of this.... I know I seen something about a checksum popup before the killer flash was uploaded.

Thanks a ton for that bin, it worked great... I took the chance tonight without a spare and went ahead and flashed the 94 tune you supplied; my torque converter is now locking up like it should, and my speedo isn't 15mph off still.... and most importantly my shift points are back I can actually cruise at 2200rpm instead of 2800...

Now I just wish I would have went ahead and lowered those fan temps, applied the WOT BLM Locker and maybe even dropped the shift points a little more to help with the slapping rev limiter; also sometimes when it kicks down it slaps rev limiter then goes to next gear, I need that tuned out... I guess now that I know I can do it myself I will have to make some more changes and flash my spare when I get it... definitely will want a new spare.

Do you guys know anyone who fixes bad PCMs?

[kur4o]

With 3500 rpm stall torque converter, upshifts doesn`t work because of the stall wall.
It`s known problem with the lt1 pcm.
Do some google search how to fix that and post the working formula.

Transmission is different between 94 and 95 and you shouldn`t mix bins.

[JustinSEO]

With 3500 rpm stall torque converter, upshifts doesn`t work because of the stall wall.
It`s known problem with the lt1 pcm.
Do some google search how to fix that and post the working formula.

Transmission is different between 94 and 95 and you shouldn`t mix bins.

That is what I was thinking, the stall definitely has a part to play in that. I will do some checking, and probably talk with Keith of PCMFORLESS to see what they do for large stalls like that if he'll share!

I didn't mix the bins, I wanted to copy values over but it is not necessary now that I have a stock 94 bin that is up-to-date... I don't think I have ever clenched my cheeks so tight while watching that flash; haha.

[lionelhutz]

I thought it was that the VSS code would get set with a higher stall?

You should be able to enter low mph upshift settings into the kickdown tables and then use the rpm table to select the shift point. I've never read anything that says you can't tune for the converter, just that the car won't shift with a bigger stall when it's a stock tune.

I had to fix my PCM in the fall. I tried to change a table in Tunercat while flashing - don't do this....

[JustinSEO]

I thought it was that the VSS code would get set with a higher stall?

You should be able to enter low mph upshift settings into the kickdown tables and then use the rpm table to select the shift point. I've never read anything that says you can't tune for the converter, just that the car won't shift with a bigger stall when it's a stock tune.

I had to fix my PCM in the fall. I tried to change a table in Tunercat while flashing - don't do this....

Well I am unsure of how I would fix it, I am definitely not very handy with a soldering iron (haven't messed with them much though)...

This sounds like a good idea with the low MPH upshifts, but wouldn't it bother the cruising speed shifts? I am gonna try to up that VSS diagnostic enable to 4,000 RPM and see how that helps me out. I haven't ever seen the "limp mode" where it will only stay in 2nd and 3rd; but I definitely see it hitting the rev limiter on upshifts on occasion and sometimes the car downshifts right into redline requiring an upshift right after!!

I do not plan on changing any pressure or shift times really because I cannot afford to rebuild a trans right now; I already have a shift kit and it shifts pretty good... smooth and still "strong". I'd rather keep it safe.. I would like to see WOT up/down shifts be tuned out; I guess it is just trial and error, gotta get a spare PCM and mess with it.

[sherlock9c1]

The problem with bricked LT1 pcms is that it's cheaper to get another one out of a junkyard than it is to try to fix it. You've gotta unsolder a tiny chip, flash it with a chip flasher ($100 or so), then reconnect it onto the board, either soldering or soldering a socket on the board and then putting the chip in there in case you get another write failure. there are two memory chips on the 8051 boards; usually I've only seen one fail (it switches over at 50% loaded, which is why it hangs for a few seconds then continues loading).

[JustinSEO]

Well I guess I will just scrap my spare and get another... Sounds like to much work to fix them. I thought I heard of a guy fixing them for cheap though....

Any other tips for the tune? I would like to have a dyno tune but nobody tunes lt1 cars around here... I want to add some timing and get my AFR corrected to make some more power and take advantage of the CAi and cat back... Obviously the stall and trans need a tune badly

[lionelhutz]

I don't know of anyone that fixes them now. There were a few people that used to do it but they quit, likely because there wasn't much demand. If you're interested in selling it I might fix it myself and keep it for a spare. I only have the parts to fix 1 more.

First thing I'd do with the transmission is drop 10 or 15 mph from the kickdown mode table. Then, drop the rpm in the rpm table to around 5000rpm. Try it and see where it shifts. Then adjust the rpm table until it shifts where you want the shift. Log it and pick out the speed and rpm you get right when it shifts. You can use the speeds in the main shift table so the kickdown and main speed tables blend as you transition to WOT.

[JustinSEO]

Well, I'm back and I just read through all of my posts... I sounded like a complete noob. :mad1:

Anyway, been logging daily with steveo's EEHack and tuning with TP and TunerCat, have got some good results thus far on the transmission tables and handling my stall. I am now researching into VE, MAF & O2 tuning for part & wot/PE tuning.

As of right now, my BLMs are around 113-122 at 0-20% TPS with the right side reading a little richer due to the left o2 dying on me last week and i COULD NOT get the right one out to change them both.. will have to try and tackle that again this weekend. Cleaned the MAF, made sure no vac leaks... I would like to work on my part-throttle stuff a little more before the upcoming dyno day so I can focus on the PE/WOT tuning with my fresh wideband install then. The consistency of a wideband at cruise is bad; so i'm guessing you guys are tuning at part/cruise via BLM?

Thanks for all the help thus far guys!

*edit > also found that my current PCM in car is running a B-Body Knock Module... Placed the LT1 F-Body Knock module from my spare pcm in it to see how that helps with the remaining knock retard.