97 Sunfire won't upshift - Maintenance and Repair Forum

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97 Sunfire won't upshift
Sunday, June 21, 2009 7:32 PM
A friend of mine brought his 1997 Sunfire 2.2 w/3spd auto over and I informed him that his trans was jacked. Black sludge in the fluid.

I went to the local U-pull-it and purchased a 3 speed from a 1999 Sunfire. I went to install it. Only mishap was I forgot to unplug the VSS when old trans came out and the wires got damaged. I de-pinned the plug and shortened up the wire and re-pinned it. I looked up the correct pin on the plug and Mitchell On Demand says that Yellow wire goes to "A" pin on the plug. Purple to "B".

Car feel perfect all through first gear, but will not upshift to 2nd or 3rd. Gear selector does not help either. Fluid has been topped off 3 times and after about 30 minutes of running will not accept any more fluid, nor will it upshift.

The transmission was taken from a car with excessive front end damage, blown air bags, and police paper work from the accident report. Mileage is unknown but it seemed like the best transmission they had. It should have worked.

VSS is plugged in, but due to late night and work early, I had to pack it in and it has not been tested. Downshift cable seems to be installed correctly, and no slack in line. All plugs are in the trans correctly it appears.

I made some attempts to "trans slam" it, but the engine did nothing but bog down.


I am trying to help this guy, and I really do not want to change the transmission again. This is identical to the issue he had with the last transmission. Is there a possibility that the VSS wire was more damaged and can cause this?

Any input would be greatly appreciated.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me

Re: 97 Sunfire won't upshift
Sunday, June 21, 2009 8:15 PM
Just a thought, are the 3 speed autos a 3T40E? The "E" would designate that the shifting is controlled electronically, and since the owner had a problem with the previous transmission then this could be a computer related problem. Only other thing I can think of is if you've ever pulled the valve body cover off of a 3T40 you know how crud will build up there. Personally I don't know why the need for electronically controlled transmissions, my TH125 and TH440 do just fine with a TV cable.




Re: 97 Sunfire won't upshift
Sunday, June 21, 2009 8:19 PM
I found no reference to the "E" when searching for this car. Owner was also wondering about the computer.

I tired to run the codes on the car, and cannot even get the terminal port on the car to come on at all so my scanner cannot even see the car. Which is a first for me. I tested scanner on second car to verify it was working correctly. It was.

BTW, reverse works correctly.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me
Re: 97 Sunfire won't upshift
Monday, June 22, 2009 4:34 PM
Did you check the cigarette lighter fuse when you couldn't hook up a scanner? Also if this is a computer controlled tranny you run of the mill $75 code reader isn't going to cut the mustard. Need something to actually see what's going on. Still have a sneaking suspicion that transmission has electronically controlled upshifts. I've found reference to a 3T40-E on the web, and by '97 (or especially '99 since that's the transmission you pulled) I would imagine that would be the transmission used. HOPEFULLY someone with a three speed knows for sure and can speak up.




Re: 97 Sunfire won't upshift
Monday, June 22, 2009 4:53 PM
I looked it up on Mitchell on Demand. It mentions nothing of a trans computer. I thought only the 4 speeds had that. Hollander exchange says this trans is a direct replacement.
The scanner does not even read power to the port under the dash. So blwn fuse seems likely. This scanner should be able to read and faults in the system. The CEL works, and is not on, so if there was a trans ECM, it would throw a code I'd think.

What is the line on top of the transmission? It seems to be a vacuum line, but was wondering if it is a purge valve/drain. If it is a vacuum line, can't I just hook it up to the intake straight and see what happens?


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me
Re: 97 Sunfire won't upshift
Monday, June 22, 2009 9:11 PM
On my '94 with a TH125c aka 3T40 the only thing I know of going to the top of the transmission is the TV cable that connects to the throttle linkage, which coincidentally is used to control the shifting. To my knowledge these transmissions never used a modulator valve. To adjust it there should be a tab to press in that will allow you to pull the cable housing away from the throttle body. The the throttle body needs to be rotated manually to its WOT stop. It's best to do this by hand and not by the accelerator pedal. Double check that the TV cable is actually hooked into to the cable in the transmission and if worse comes to worse you can always pull the side pan and make sure the cable is actually connected inside the valve body as well. Operating the throttle body should operate the linkage inside the transmission.





Re: 97 Sunfire won't upshift
Tuesday, June 23, 2009 4:06 PM
Yeah, it took me a minute to figure out how that cable detached from the old trans, but I am pretty sure it was hooked up. I will see if it has slack in it and if any play is detected. I however thought that that was mostly just for the sake of getting a downshift passing gear if you are at WOT though? Not for upsift? I suppose that if it had tension on it though, it would always keep the trans in 1st gear, and not allow an upshift. I'll unhook it from the TB and see if the car shifts then.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me
Re: 97 Sunfire won't upshift
Tuesday, June 23, 2009 5:15 PM
If it shifts I believe it will slam into gear iirc. TV cable controls upshifts/downshift feel. Could probably google some good write ups on TV adjustment for a TH125 or TH440.




Re: 97 Sunfire won't upshift
Tuesday, June 23, 2009 5:36 PM
Well no shifting of gears has happened. I removed the cable at the TB, and pulled it. You can hear the click and what feels like a spring or something resisting the force. I did not pull very hard. Drove around with the cable detached and nothing happened.

I talked to a guy on the phone who says that it could be something to do with the discs inside of it being damaged from the accident (the car I pulled trans from was in a fender bender).

I have been googling the hell out of this trans. Finding lots of information, but it seems that removal of the side pan is the end result of most of them.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me
Re: 97 Sunfire won't upshift
Tuesday, June 23, 2009 8:50 PM
I know there's a write up on a Fiero about installing a shift improvement kit which could get you started if you decided to pull the valve body to clean. Also wouldn't hurt to pull the governor for cleaning.




Re: 97 Sunfire won't upshift
Saturday, June 27, 2009 5:02 PM
I opened up the old transmission and am more confused than when I started. I really regret offering to help this guy out. I have replaced about a dozen transmissions, and never once had a problem til now.

I identified a few parts, but this is 100% foriegn to me. I would not know if or what is wrong with a part.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me

Re: 97 Sunfire won't upshift
Sunday, June 28, 2009 7:16 AM
Replaced the govenor and that did nothing. Tried to do a few trans slams again. No results. Other than the car almost stalling because the old ass 2.2 is a gutless wonder.
Found I had a weak ground signal though. Fixed that, but car seemed un-effected. I looked at taking off the valve body, but I'm afraid to tear that thing apart and screw anything up.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me
Re: 97 Sunfire won't upshift
Sunday, June 28, 2009 10:49 AM
So I checked ohm resistance att eh terminal for the solinoid and the 3rd gear switch on the transmission. I get nothing. I test the solinoid I have in the extra transmission and it reads correctly. Something like 29 or something. However, when I hook up that same solinoid to the extra trans, just to see what happens when I have the switch also in play, I get no resistance at all.

I do not get it.

To recap:

extra solinoid reads perfect when in hand and is the only part being tested.

Add in 3rd gear switch and the resistance stops completly. Which is exactly as the car is now.



I guess taking off the side cover and testing that way is the only solution. Testing each part independantly of each other.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me
Re: 97 Sunfire won't upshift
Sunday, June 28, 2009 4:59 PM
If you're reading the circuit as a whole then you shouldn't read any continuity because the TCC solenoid and 3rd gear pressure switch are in series, and you won't make the switch until you're in 3rd gear. In actuality those two items aren't needed for transmission shifting, only the locking of the torque converter clutch.

This is definitely effed up as the TH125c is a pretty rugged transmission behind a 2.2L.




Re: 97 Sunfire won't upshift
Sunday, June 28, 2009 6:34 PM
Well, I swapped out the solinoid, but due to it being late (work early) I have not test driven it. If this does not work, I will drop trans and return to junkyard and pull another and install that.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me
Re: 97 Sunfire won't upshift
Sunday, July 26, 2009 2:05 PM
any updates on this one? My 3 speed 3t40 does the same thing. from what I read, this is not a computer controlled trans. Some have told me to adjust the TV cable. But I believe either the governor is sticking or the valve body is full of crud. A tranny fluid change with Maxlife ATF and Lubegard red has helped unstick the gears. I got 165k miles on my trans.
Re: 97 Sunfire won't upshift
Sunday, July 26, 2009 7:38 PM
After testing everything I could, I in the end decided the internals of the trans must be bad and replaced it again with another JY unit. Car shifted perfectly then.

The cable can be an issue, but pretty easy to check if it is sticking. The govenor is easy to check too. Taking the solinoid out took about 45 minutes to 1 hour. Easy enough, but I hate that little bar they put on the trans mount. I removed it ASAP.


-------------------------------------------------------------
Quote:

Someone in my class made a good point about Isuzu turbos...they're almost as big as GM alternators.


1992 Isuzu Rocket 2.3 HO
Chassis by Isuzu
Powered by Oldsmobile
Brains by Megasquirt
Built by Me
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