Weird A340e shift problem

[mikeymkll7mgte]

Car- 82 Celica Supra. 7mgte, Megasquirt, stock gte A340E trans with stock gte trans computer. Im using outputs on ms to the ect ecu for the tps signal that the ect ecu recieved form the stock engine ecu. Hope i have not lost anyone yet! It shifts flawlessly, and is an absolute blast to drive. Anyways, when im up in revs and speed, and i shift into neutral, the rpms drop for a split sec, then jump back up for a few seconds, then it goes into neutral. It acts like it goes into neutral, then grabs, and it will slam you forward, then goes back into neutral. If anyone want to see it on a datalog, i can load one up to see what i mean. I thought when you shift it into neutral, it is supposed to go into neutral, not have a delay kind of thing like it has. Any questions just let me know, and any solutions to this kinda annoying problem (especially at the dyno!), please chime in. Thanks

 

[IJ.]

Unplug the ECT and see if it does the same thing.

The manual shift body should override the ECT 100%

N should be N the delay's are only while shifting into D or R.
(Suspecting a incorrectly adjusted shifter)

 

[Nick M]

The converter may be locking and unlocking. More than just the TPS is input to the trans computer.

 

[Nick M]

Unplug the ECT and see if it does the same thing.

The manual shift body should override the ECT 100%

N should be N the delay's are only while shifting into D or R.
(Suspecting a incorrectly adjusted shifter)

Yep, do the manual over ride first.

 

[suprabad]

Sounds like it might be a bad solonoid. If one or more of them is not working properly it can cause all kinds of anomalous behavior.

Easy to check, easy to fix.

Beware...when they go haywire, frequently the problem will be intermitent, which obviously makes it harder to pin down. Best to replace a suspect solonoid, rather than to try to determine if it's malfunctioning intermitently.

 

[jdub]

Before you start replacing solenoids...the TSRM has a series of manual shift tests like IJ said...do them. It will also throw ETC codes...check them.

 

[mikeymkll7mgte]

It does it with the ect plugged in or unplugged. It does it on the dyno with the ect out and a switch to lock and unlock the converter, and on the street. With the ect unplugged i can do all the manual shifting tests and it works perfectly. The trans only has 17,000 miles on it. It only does it when going pretty fast and then shifting into N. The engine will slow down for a split sec, then act like you took it out of overdrive while moving pretty good, then it will release and go into N after a sec or two. A friend of mine, who is a ase master tech, thinks that it may be setup that way because in N there may not be much fluid flow, but you are still moving, so it might be there as a safety thing. Its really not a problem for me, as i never really do it, except at the dyno, but its more or less just a little quirk that i would like to know why its doing it. Thanks so far for all the help.

 

[mikeymkll7mgte]

And i know that more is input into the ECT ECU than just the tps signal, so to be technical- The OD from the ecm is always hot, so it shifts into od anytime. (dont worry, i let the car warm up to at least 140 before i go anywhere) i have an od and pwr/norm switch. Then there is the idle and the 3 tps inputs that MS controls.

 

[Nick M]

Why are you shifting into neutral when you are going pretty fast?

 

[mikeymkll7mgte]

I only did it on the dyno, after a full run, cause the dyno operator said to. He thought it was wierd too. And then i tried it on the street just to see if it was because i had the ecu unplugged, and it did it there too. I have not done it since then, as there is no need too. And by pretty fast i mean in the neighborhood of 50 to 70 on the street. On the dyno it was around 116 and about 6500 rpm. My main thing is i want to know if this is normal or not. If not, i want to figure out what is causing it. If it is normal, then so be it. And im not tryin to be a pain, incase i might offend someone. I know my car inside and out, and this is one of just a few little bugs that kinda bug me, so maybe one of you that has a bit more experience than me may know whats up. i will get a screen shot of my datalog on here tomorrow, incase someone does not know what i mean.

 

[Nick M]

Make sure the range selector on the trans is nice and tight. And adjusted correctly.

 

[mikeymkll7mgte]

ok. I will double check it tonight.

 

[IJ.]

:nono:

 

[mikeymkll7mgte]

ok... so why is that???

 

[mikeymkll7mgte]

im all ears to anyones suggestions.

 

[IJ.]

ok... so why is that???

2nd post I suggested a logical approach to diagnosing what it's doing.

You haven't done what I suggested now you have suggestions that it could be the solenoids...... why not change the dome light bulbs it might be that as well.....

Start at step #1 and work the problem don't jump all over the place changing things it "might be" ..

 

[Buddafucco]

sorry- fixed

 

[jdub]

Funny...2nd step says check tranny codes. IJ told you to do a manual shift test in post #2, I told you to check the codes in post #6. I wonder where we came up with it

 

[upgradedsupra]

Car- 82 Celica Supra. 7mgte, Megasquirt, stock gte A340E trans with stock gte trans computer. Im using outputs on ms to the ect ecu for the tps signal that the ect ecu recieved form the stock engine ecu. Hope i have not lost anyone yet! It shifts flawlessly, and is an absolute blast to drive. Anyways, when im up in revs and speed, and i shift into neutral, the rpms drop for a split sec, then jump back up for a few seconds, then it goes into neutral. It acts like it goes into neutral, then grabs, and it will slam you forward, then goes back into neutral. If anyone want to see it on a datalog, i can load one up to see what i mean. I thought when you shift it into neutral, it is supposed to go into neutral, not have a delay kind of thing like it has. Any questions just let me know, and any solutions to this kinda annoying problem (especially at the dyno!), please chime in. Thanks

As stated, IJ has a valid suggestion that would get you in the right direction, so why not listen?

In case you forgot this is a good start (see below)

2nd post I suggested a logical approach to diagnosing what it's doing.

You haven't done what I suggested now you have suggestions that it could be the solenoids...... why not change the dome light bulbs it might be that as well.....

Start at step #1 and work the problem don't jump all over the place changing things it "might be" ..

Then you have step 2 (see below)

Funny...2nd step says check tranny codes. IJ told you to do a manual shift test in post #2, I told you to check the codes in post #6. I wonder where we came up with it

please chime in. Thanks

No need for me to start another step since you haven't followed these yet. People are here to help you as long as you are willing to listen.


Duane

 

[mikeymkll7mgte]

no codes. ever. trans shifts through the gears in the manual test as specified. car shifts and drives perfect. solenoids check out fine. lockup solenoid is fine. sorry for not being clear enough that i had tried all these things already.