Automatic transmission problem
 

Okay first of all the car has a Sprintex stage two on and then normal headers with de-cat and then just a normal cat-back exhaust.It has a stage 2 flash from delicous tuning and we have swapped 3 diffrent tunes so we know it is not the tunes.

Now the problem is when i give it the beans,the car seems to select the next gear but doesn't engage it almost like a manual has it's clutch in and revving it. :mad0260:

[ame]http://youtu.be/Z5fGqvOrmjY[/ame]

Stock trans? Looks like its got clutch slippage.

Edit: never mind, im clueless......if it was clutches slipping your rpm would still go up......yours seems to get stuck.....perhaps torque converter is locking?

Agreed. High torque loads on the clutch will cause this. That's why the invented sport clutches.

1. Check your fluid level
2. Does it do it cold or hot or both?
3. Does it do it in manual or auto mode or both?




If it's engaging the next gear but slow to "take up" it's probably a clutch/plate issue in the oil pump or a sticky solenoid in the valve body.
I'm guessing but that's where I'd start.

My A/T did this with an SBD turbo on only 7 lbs of boost. That's why I sold the turbo. I'm working on a way to rear-mount a used stock Garrett off an R34 Skyline GTR. It's one of those with ceramic blades that people hate because it starts to break blades over 14 PSI. I picked up 2 of them for $50 each. I want to adapt a muffler delete into the turbo hotside inlet, a tailpipe onto the hotside outlet, a cone filter and adapter on the coldside inlet, and a finned tube going to the front into a Phantom electric supercharger. This will give instant boost, yet when the Phantom peaks and starts to drop off, the rear-mounted turbo will fill in. Best of all, this can all be installed on a stock exhaust with all cats installed, so it will still pass DEQ.

I called that symptom, "all-gears mode" when I had my turbo. It seems to only happen under boost. I couldn't shift up or down with the paddles or the floor shift until I let off the gas. This is why I signed up for the Phantom. The boost is only temporary, and it's much lower. I think the transmission has some kind of torque limiter in the shift controller. That's just the kind of thing that makes me want to crack the code and reprogram it.

Kris @SSP has been seeing a lot of A/T failures lately under boost. The bad part is that some of the failing parts aren't available anywhere but from a donor tranny. I have his stage 2 valve body and cooler installed. The clutch plate kit is sitting here ready for when those start to slip. I would ping Kris to see if he has any ideas.

We already changed the oil 2 times. We think it is electrical but as you suggest it can be a sticky solenoid in the valve body but , wouldnt toyota pick up on that when it was there for the trans problem? It happens very slightly when cold but when hot, it is as aggressive as in the video. And yes it is a stock tranny

Thought I broke an axle first time it happened to me (cause I just read the broken axle thread.:D) but the free revving, no power is the same feeling when I hit the rev limiter.

I've got FI AT also and it just doesn't shift as fast as we'd all like I bet. In manual mode, shifting a little sooner and I avoid it. In Auto mode the ECU doesn't make the same mistakes I do when up-shifting.

Styx, You see the same thing when in 'D' ?


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“The thing is, it’s a gearbox, okay? It has one job to do! One job! Pull the lever… ‘Am I a pencil? Am I a cauliflower? Am I a nuclear power station – I’m a gearbox! Oh, heavens, I’m gonna swap some cogs around!’”

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It happens in D and in manual mode and it happens only in wot, when in manual or in D between 3 and 4000rpm it shifts fast without any problem

I wish I could drive the car to see what it feels like its doing. I really think its something torque converter related though. Just seems from the video that when you shift gear it wants to accelerate but its being loaded down by something cuasing rpm to remain stationary, but then when you lift and re apply throttle the load goes away and it accelerates like normal then.


This is just from what I'm seeing and hearing though, its hard to give definite diagnoses over the internet. Do you have any way to log or visual see what's going on via a tablet or something?

So if you stay between 3-4k and do WOT shifts does it still slip?

Just trying to get idea if it's only high RPM and WOT = slip.

I dyno'd 250whp on 93 but now with e85 and cranked up boost I don't even know how much power's there but I haven't had any problems except kissing the rev limiter like I said. knock wood..

We keep our foot planted in the video we never take it off it just engages when it wants too.i do have logs with ecutec software but that is at the guy that does my reflashes.

Normal 3 to 4k driving it doesnt happen only when in wot and in high rpm it does that. The car only puts 158kw too the wheels so i dnt know why its giving us this crap

My unprofessional gut opinion is still telling me rev limiter, which would be good because it would mean your transmission is fine.
If you deliberately plow it right up to redline you'll see what I mean.

If your buddies with your tuner talk to him about it and discuss raising the limit ~200rpm and test again in D.

My current theory is the momentum from the extra power is spinning up the engine just past redline during the AT shifts? :iono:

Okay but why does it do the same when in drive ? So it cant ba a rev limit thing

What I said. You've got a more powerful engine the TCU doesn't know anything about. TCU has yet to be cracked.
Even in D the TCU says: "Shift Now!", but the engine is still riding that extra FI through redline as the transmission is working on the shift.
Then the ECU is like "Oh Crap, what just happened? Better cut the power to keep from blowing".

I don't know bro....My comments are all theoretical.
Here's some chat about the same with some stock, high HP cars.

http://www.challengertalk.com/forums...69/index2.html


http://www.corvetteforum.com/forums/...-one-else.html

Apologies, i must've miss read something or confused myself with a different thread.


In any case, you should definetly look at the logs before jumping to any conclusion from us here. As you can see some are saying granny problem and some are saying engine/ecu, so your not going to get a clear answer.

Do you have an afr gauge in the car?

The a/t doesn't have the same rev limit as the manuals have. It hits hard. The OFT guys change it by copying the limit from the m/t tunes to make it a "soft" limit. I strongly recommend having your tuner at least copy the rev limit from a m/t tune to your tune. That could fix the problem right there.

So did you get it fixed?

I have a vortech SC on A/T as well. I was running on delicious tuning remote tune and after 3 revision, i started to have the same problem with whats happening on the video. But after getting the car dyno tuned, shifting went really smooth and they squeezed out more HP.

So unless youre certain that theres a problem with the transmission, i would get it dyno tuned. I THINK theres something to do with the shift points as stated above post. Its like getting a tuxedo tailored exclusively for you (dyno tune) vs buying a ready made ones (remote tune/ off the shelf tune) lol

When I had my SBD turbo, I was using OFT tuning, and I had a very similar problem. I talked about it with Chris of SBD and he said something like "All the other automatics used Ecutek tuning and didn't have any shifting problems." From this and other inferences, I would deduce that neither Delicious tuning, nor Open Flash tuning have access to certain tables or inputs that Ecutek has, and since it only happens with FI, it probably has something to do with the MAP sensor, or with manifold pressure limits. Dyno tuners usually use Ecutek, so that's why dyno tuning usually fixes the problem.

I forgot to mention when i got my SC, i was asking openflash if they can give me the tune for the OFT300. They were concerned about the shifting smoothness so they end up not sending me the tune. Although OFT is really convenient and it can monitor lots of parameters. I had to switch to ecutek to get the most out of the FI setup. DD drivability and flexibility when it comes to tweaking your setup, ecutek is the way to go.

I'm experiencing the same issues with my auto trans and FI, kraftwerks c-38 running E85. Anytime I'm above about 8 PSI it feels like the clutches are slipping. I'm Ecutech turned (remote by motoeast).
I'm thinking about replacing the valve body, clutches, and torque converter with SSP but that's a lot of money to find out it is an electronic issue not a mechanical one.

I'm having the same problems as well. I'm running the AVO kit and under hard driving the rev would climb but the wheels are not moving and the shifts are really slow. Need to back off the throttle before the gears are engaged.

1.
"Kris @SSP has been seeing a lot of A/T failures lately under boost. The bad part is that some of the failing parts aren't available anywhere but from a donor tranny."

Do you have any more details? What parts have failed?

2.
I have an Ecutek-tuned GTX28 AT with map switching. The first map has approximately 370nm of torque. All is fine. The other maps have more than 400nm of torque. If I accelerate hard, it seems that the clutch is slipping. Moreover, check engine lights are shown. I read out the error codes:

C1294 = ECT System x Function
P2757 = Torque Converter Pressure Control Solenoid Circuit Stuck

Does anyone have experienced the same issue (including check engine lights)?

3.
Initially, there were reports from tuners that they run their AT with 450 whp. They did not report any problems. Does anyone know how they solved/avoided the problems mentioned in this thread? Or did they simply not tell us about these problems.

Thanks.

:popcorn:

I will say this though, it sounds awesome:burnrubber:

Still the same issue, even stock
 

Thanks very much just to give you guys an update my dad has since removed the supercharger and returned it to stock except for the exhaust. My dad thinks it may be the torque converter because it is back to stock and when the gearbox gets backup to temp and flooring it again it does the same but only lightly now....so we don't know any suggestions, can it be that the thortlebody got too warm and is getting stuck on the shifts or can it be that the thortlebody just has so many shifts before it acts up ??

Only thing I can think of is replacing fluids and trying to get a transmission cooler if you plan on putting the supercharger back on. Highly doubtful of a throttle body, throttle bodies don't get stuck and skip up RPMS and dance around like that, it's something mechanical related to the transmission, may be time for an SSP clutch pack install and valve body replacement....

Something mechanical. Im putting my money on the TQ converter.

Styx.. ECU also back to factory tune?
Is really unfortunate for you/us all... Now I wonder how much longer I have left in my AT.

It's kind of worrying unlike the manuals which have proven themselves for the most part reliable till 280 whp+ on stock clutches and such, the autos haven't had much testing in that department.

Yea well according to some the gearbox can handle 450HP easily!! I think those guys just forgets to mention the gearbox upgrades.!:mad0260:

Just to remind everything is back to stock the motor,ECU everything except the exhaust with a high flow cat in and axle back exhaust in. The problem exist still but we don't know what the problem is really and is scared to buy a new well anything because we may end up paying for something that wasn't needed... Just scared for the cost, for the most part other then that we would love too get it fixed.

I'd recommend taking it to a dealership, they'll be able to fix it if it is a TCM issue, they'll also be able to diagnose if its a mechanical issue at which point it can be taken to a transmission shop for much cheaper

We have replaced the transmission fluids 2 times have taken it to toyota 2 times and none of them can tell us what is wrong.:mad0260:

I too am running into issues
 

So I just wanted to chime in and say that I'm also running into the same issue.

I'm boosting 8psi on a AVO kit and I will be taking that up to 12 psi with E85 soon.

I'm getting a tyranny rebuilt by SSP with a set of their Stage1 clutches, their stage 2 valve body and their higher stall torque converter. I'll report back what I find after I have broken in the transmission and put a 1000 or so miles on it.

I have a theory, and I'm putting it out there for the back-seat drivers to shoot holes in and insult me, but also for the few serious tuners to try out and see if this fixes the problem.

Since these cars are Drive-By-Wire, it would make sense for the pedal input to be sent to the transmission controller. What if the DBW table is too aggressive? What if the table just needs to backed down some so the car is making the same power at the same pedal travel, and really cranks up at the end of the travel? The MT DBW table is less aggressive than the AT DBW table. Maybe try that out and see if there is any difference in the full-load shifting problem. I personally would like it if someone found some kind of back-door into the TCU with Toyota's Techstream software.

I've looked into the later, the only thing you can do in techstream is reset the TCM. I also think there was an option to update the TCM logic if neccessary.

How long have you had the turbo? And how well did the transmission behave before the rebuild?