Car doing weird stuff (fuel cut and auto tranny problem)...

[Funkdariaa]

Allready posted this on CR, so if you looked at it over there and/or replied, this is the same exact post so don't worry about it again.

As far as I can tell, two totally different problems, but I'm lazy and don't want to make two post. For background, thoes who don't know: 92 eagel talon tsi awd w/small 16g, full exhuast, k&n filter, mbc set to 10psi, automatic.

First problem: When going around corners the engine just dies. I'm assuming it's losing fuel. I've read stuff about the pickups in our cars not being so good and if you autox/road race/go around any corners you shouldn't let it drop bellow 1/4 of a tank. Well it's never done this before, even on E. It did it a few times when I had a little less than a quarter of a tank in the last month or so. Well two days ago driving home I had a supposed half a tank (backed up by me geting gas the next day when it read 3/8 and it took 8gals.). It did it three different times on the way home around corners. I also looked down after some long sweeping corners and my low fuel light came on for a half a second.

Second problem: That night before when my car was cutting out around the coreners, other than that problem, it drove fine. This is the one that really concerns me. Went to meet my mom at the krogers ~1.5 mi from our house. Car wouldn't shift out of third. It wouldn't shift on it's own or if I tried to manually shift it. It did this on the way there and back (after sitting for about an hour). Remember, it ran fine to appelbees and back the night before. Let it sit in our driveway for another hour. Took it for a ride and it was fine, it's been fine since then too.

Any ideas would be greatly appericated. Thanks all, later.

UPDATE:
Well wtf....
It did it again today, but then quite again after two on of cycles, just like last time.
ie: runs fine, turn off car, turn on car, only 3rd gear, turn off car, turn on car, only 3rd gear, turn off car, turn on car, runs fine.

Don't know how many times I've started and stoped it sine it last did this, but I've driven about half a tanks worth of gas since then, all the time working fine. Only unifying factor either time when it started was my car was very cold (as in hadn't been started in a quite a few hours), and it was very hot outside...

I'm just about to say fuck it and do the m/t swap, I've been wanting to anyways, just not now (money)...

[BlackEclipse]

I've been below a 1/4 tank and have never had a problem with the car dying by taking a corner fast but then again, I have a different gas tank than you do because my car is FWD.

[Auto1g]

Hello,
I seem to be the resident AT expert (I use that term loosely). I can pretty safely say what is wrong with your trans. It is going into safe mode. It is something the TCU does when it senses something electrical wrong with the tranny. There are two possible problems. One the TCU is going bad. Which is what I would guess. There are capacitors in it just like the ECU that goes bad. Or it could be the electronic connectors (not sure of technical term off hand) on the trans. When the go bad it'll do the same thing. I would first check the TCU. If it was the connectors it would stay in safe mode always. I would say the TCU is going bad . That is probably why it is an intermittant problem right now. It will only get worse. I would pull it out and check it. It is above the ECU behind the radio. If you have any more questions feel free to email me.

Pavo
pavochavo@hotmail.com
91 GSX AT 11.65 @ 117

[Iwishiwascool]

Definitely the AT expert.

[Funkdariaa]

Hello,
I seem to be the resident AT expert (I use that term loosely). I can pretty safely say what is wrong with your trans. It is going into safe mode. It is something the TCU does when it senses something electrical wrong with the tranny. There are two possible problems. One the TCU is going bad. Which is what I would guess. There are capacitors in it just like the ECU that goes bad. Or it could be the electronic connectors (not sure of technical term off hand) on the trans. When the go bad it'll do the same thing. I would first check the TCU. If it was the connectors it would stay in safe mode always. I would say the TCU is going bad . That is probably why it is an intermittant problem right now. It will only get worse. I would pull it out and check it. It is above the ECU behind the radio. If you have any more questions feel free to email me.

Pavo
pavochavo@hotmail.com
91 GSX AT 11.65 @ 117

Cool, i'll pull it sometime this week and check it out. if the caps aren't visually leaking and I pull them, what should the values be (or are they marked)? I guess I'm saying how should I diagionis it, i have a bs in electrical engineering and a voltmeter with a cap. measurement thingey on it, so point me to the right direction on what do on it and i'll figure it out. Just don't have a factory service manual yet... :confused I should really get one of thoes things.

Once again it did that the first time either wed. or thur. of last week (can't exactly remember), and the second time on fri. Drove to work and back on sat. to mid-ohio, around mid-ohio, and back, and it was fine the whole time.

Once again, thanks tons for the help.

[Funkdariaa]

Damnit all to hell and back. I took all the stuff apart to get to the ECU and TCU (going to replace all caps), and can't see the TCU. Where is it.... Also there are three electrical pin out connectors on the ECU, got both outsides one off, but the middel one is broken. The little tab that you depress to release the connector is broken, not there. But the part of the tab that is used to keep it in is still there. There are two little 'tabs' on the outside of the big tab on all three that are also still there on the broken one. I've been sturgling with this thing for about half an hour trying to get it out. :bash Fingers, screwdrivers, can't get it to come out. Any tips on how to get this thing out. :bash

[Auto1g]

I am not sure about the values. I don't have a manual either. If anyone has a dsm cd can you give us a hand? The tcu should be above the ecu. It isn't easily visible. It is sort of right behind the radio. Kind of tricky to get to. I'll have to look into this further. Only thing i know is what happens when it goes into safe mode and what can cause it. I'll get back with you.

Pavo

[Funkdariaa]

I'm sure I'd be able to see it if I got the part of the center consel out that has the hvac controls on it, but I can't seem to remove it. The screws at the bottom bellow the stereo are out, the two to the left that also hold the dash cover on are also off, but something else up top and/or on the right side are holding it on.

I found a sight for pulling codes from the TCU so I was gona reconnect my ECU (never got the messed up connector off, so it's just the two easy ones) and see if the codes from the TCU are still there.

Thanks for all the help.

[koritina]

Screw behind the center vent. It's fun getting the vent out without breaking it. If it breaks I have a gauge vent that goes in there. :D

[Funkdariaa]

Cool... but is that where the TCU really is on a 92? Frankly I'm bending down as far as I can and I don't see shit up there except for the HVAC controls. I see what appears to be two smaller control units (maybe) that are about level with the bottom of the ecu, but closer to the shifter/ebrake.

One is mounted on the same metal piece as the right side of the ECU, it's metal, has the dsm logo on it and a few numbers. The other is a plastic box that is mounted on a piece of metal that goes in bettwen the other two pieces of metal that the ECU connects to. It has no markings on it that I can see and it is gray. Both of these 'boxes' have pinouts on them.

Oh yeah, I reconnected my ECU and went to rat shack to get some aligator clips to try to pull the TCU codes. It did the whole third gear thing again on the way there, but not on the way back, so it seems to be doing it more often. I tried to pull my TCU codes via this page http://www.plymouthlaser.com/tcucodes.htm which I found the link to on DSMtalk under the AT stuff. I didn't see any pattern, sometimes it just sat there and bounced in bettwen 0 and 12V fairlly quick.....

[Funkdariaa]

Cool, found where the TCU is (well, at least where yahoo AT dsm group says it's supposed to be) and I believe I can see the electrical connector for it right bellow my ECU. I also found there that the voltage is supposed to constatly swing like that if there are no codes.... no codes my ass, why is it going into limp mode then. :roll eyes

[Funkdariaa]

Lol, found another post on Yahoo groups of a guy that said his tranny was going into limp mode, but the TCU wasn't giving any codes. Turned out once he got his TCU out the caps had leaked on the board enough that it had ruined it... looks like i'm taking my TCU out, hopefully all's i have to do is replace the caps.

[Funkdariaa]

I feel like Shawn replying so often to my own thread....
Done and done. One of the caps in the TCU leaked, pretty sure that's the culpurit. Gona replace all the big (electrolytic) caps in the ECU and TCU, hopefully (it should) that will fix it. For futre reference for anyone that might need it. There is another kick pannel further up than the one you take off for the ECU on both sides, this is where the TCU is. It sits perpendicular to the direction the ECU sits, but lower down on the 'floor'. The drivers side lets you get to the 3 bolts that hold it in, and the passengers side let you get to the three electrical connectors.

EDIT: Yeah, there are alot more caps on the TCU than the ECU, anyone know which ones I should replace, or should I just replace the larger ones (obviously at least the one that leaked).

[BlackEclipse]

Get a digital photo of the inside of the TCU and share it with us???

[Funkdariaa]

http://www.imagestation.com/picture/sraid73/p3ffb90383563998bbc94d2e78d43b5c3/fb682acf.jpg

Crapy camera, but you get the drift, outside is metal, but a gold color instead of the silver on the ecu.

Thoes little orange bulbs are caps too, but not electrolytic, so I'm not going to worry about replacying htem