midiwall

I have a reoccurring problem, it's back, and it's driving me nuts.

- ECT: OFF, OD: OFF
- Accelerate from a light "in a spirited fashion" but not WOT
- 1st-2nd happens normally
- Shift to 3rd happens at about 2200
- Engine bogs 'cause it's way too early

If I kick the skinny a bit, it'll drop back to 2nd and continue the normal climb threw the gears.

Seems to happen more when it's warmed up than when it's cold. Tranny fluid level is okay, if anything it's too full. All vacuum lines are in place, all electrical in/around the tranny is connected and secure.

Ideas?

marko3xl3

Yeah, I have had that happen quite a bit. When the engine is cold, it'll always shift early, but when it's warm, I can reproduce it by accelerating "in a spirited fashion" and then slowly releasing the gas in 2nd, and it might just shift early into third, which is then annoying. And most of the time I do this, it's accidental.

As far as how exactly it shifts, isn't it computer input from the ECU as well as pressure and whatnot in the valve body of the transmission?

thefallman

the A340 is fully computer controlled. the computer controls all shift points.

does it do the same thing with ECT : ON

Tanto

Mark - I have the same issue as you, but I fixed it by keeping ECT = ON all the time.

Did you have this problem before you put on the S/C?

midiwall

I think so, but ain't sure hence me asking. I think the tranny computer is piggybacked off of the ECT - i.e., there aren't any dedicated sensors for it.


Yeup, pretty sure it does...


Hmmm, see above. Maybe I'm just flipping out.

Oh man, it's been so long, but I'd have to say "no", based on it not doing it all the time now.


I'll run with the ECT shift points engaged for a couple of days and see how it goes. Thanks guys.

thefallman

the ECU contols the tranny based on what information it gathers from the engine sensors. hence not being able to run the auto tranny without an auto ecu for us swaps

midiwall

Update... Yes, it happens after everything's warmed up with ECT engaged.

argh

thefallman

sounds like a valve body issue got something in the valve body or something. like that.

snap-on

but that would mean he couldnt correct it with the skinny peddle... ie his tap of it tells the puter "hey go faster" it tells the tranny to do its thing and it down shifts again.

if it was valve body i wouldnt expect that to work.

seems electronic to me. I know my E34 bmw has electrical gremlins in the wiring that leads to the tranney ECU that causes headaches only when its cold outside.

mt_goat

I don't know if it makes a difference, but you might check the transmission cable adjustment at the throttle body.

snap-on

OHHHH i like that one

Jim McNabb

Try sending an e-mail or make a phone call to John @ IPT Transmissions. He is the guy who does valve body mods for folks with 'chargers. He is always helpful.

midiwall

Nah... sorry guys. Been there and nothing's up.

I've had the top end of the motor apart a LOT the last couple of weeks in chasing injector sizes, o-rings leaking and a couple of other things. The cabling's in good shape.

wait... hold on.

okay, I'm back. I walked out to my truck to check... it's all good. Well, it's "correct", which I guess is actually bad since that's not the problem.

midiwall

I know John... I've had mixed results in getting answers from them on diagnosing issues. Email is always "give us a call so we can talk about it" and when I do talk to them, the results are a bit sideways. Right now I'm in a debate with them about whether I can spend $700 to fix a separate issue or if (as they claim) it will cost me $4500.

marko3xl3

What you could try, is resetting the ECU via your preferred way and then drive aggressivly from the start for some days. After maybe 3 days per say, it should pretty much remember you like quick and not downshift as early, which might be annoying when you want it to (gas savings). I am currently in "gas saving" mode and my tranny just loves to shift early if I am not on it.

Adam F

http://awshifting.com/

mt_goat

This is for the A340H, may give some insight to the programming: http://personal.utulsa.edu/~nathan-b...36automati.pdf

midiwall

I tried this last night and... no good. Within 2 minutes of the reset it was shifting early. Good idea though!


HAHAHAHAH!

Yeah, I was in that thread pretty much from the beginning. I've thought about it, but to tell you the truth, the video example that Brett posted turned me off because of the lag.


Nice find Dale! {think} {think}

AaronW

I have an '86 4runner with the a340h transmission and had the same shifting problems. I read on here that sometimes the solenoids are the reason for poor shifting. So, I ordered new ones for $207.00 total and changed all 4, which took me 3 hours. My transmission shifts fine now. and that was a year ago that I changed the solenoids.

The solenoids were original and my truck has 298,??? on the body...possibly the transmission but not sure. Either way, after 20 years it was time to change them.

midiwall

Hmmm... that's interesting info. I'm about to (finally finally!) have the valve body work done, so maybe I'll do this too while I'm in there.

Thanks Aaron!

Any idea's on part numbers? These are straight forward to swap, right? You can get to them from the pan?