95 cutlass 3.4dohc auto issues

[bbeck]

This past weekend, my car started acting like the torque converter is fully locked and waits to downshift until the rpms are very low in that gear when slowing. When I take off, it starts in 1st and then partially shifts to 2nd and immediately jumps to 3rd with the torque converter locked. It then shifts in 4th (OD) early as well. I have no idea on where to start with this. The car has just over 140k on it and hasn't been abused. I'm hoping that I can get to it this weekend and do a fluid and filter change at the same time. I drive 100 miles a day, so I need to get this taken care of before I end up burning up the clutches in the trans and need to replace it. Hopefully somebody here has dealt with this issue.. Any ideas?

[robertisaar]

almost sounds like the VSS is going nuts.

or maybe TPS, since those are the only two real inputs to shift speeds.

[bbeck]

I thought about the tps as well, but it seems to run just fine with no glitches in park/nuetral when I press the gas. I haven't had to deal with automatics much, so I'll have to read into this.

[bbeck]

What's easiest/best way to tell if a speed sensor is bad? The abs light is on, would it be the wheel sensors throwing this off?

Also, the speedo seems to work just fine with no glitches.

[robertisaar]

ABS and PCM do not communicate with each other, so that's not it.

and if the speedo is working correctly, then the only other thing that effect shift points is the TPS. check it's voltage at various throttle openings, see if it's getting skewed in any way.

and just for fun: pull the ECM BAT fuse, that will reset the PCM's learned TPS stuff, just in case something odd happened and the PCM thinks something is happening that really isn't.

[bbeck]

thanks, I'll check it out after work. It would make it alot easier if I had a scan tool on hand to just plug in and check it out. I now have hptuners, but nothing for obd1

[bbeck]

I'll be checking into it this weekend since I wasn't able to pin the tps to get a reading- the engine was pretty hot after my hour drive home. But, it hasn't acted up at all since it's cooled down over the past couple of days. So, I'm not quite sure how that all plays in. I figure I'll change the filter and fluid this weekend since it's about due. Perhaps this will help.

[bbeck]

So, bringing up an old thread as it's still having problems.
The car now has 178k on it. The only thing I've done to the trans is a filter and fluid change. It has acted up in different ways since the first issue and I will try to explain.

I would like to start compiling the parts to take care of it this winter if they are internal pieces that need to be replaced that can't be done in the car. I'm not sure of the sound I hear when it is in P or N (like something loose, knocking around). I will try to get an updated video next week when I'm back in MI, as it happens more now.
Here is the first post I brought that up in: http://60degreev6.com/forum/showthre...ans?highlight=

On top of this issue, it will start to drop down into 3 from 4 after a long trip. This seems to be longer before acting up (if cooler temps outside) or shorter (if warmer).
Now, I have purchased a Tech 1 scanner over the past couple of years and have pulled the codes. I have pictures or video of all of the trans codes that I will also post once I get back to MI as hopefully that will give some guidance.

What I find odd is that I can manually request 4th with the Tech 1 while driving, and it stays no problem. There is NO SLIPPING in any gears, just a lack thereof when the tq seems to like to stay locked occasionally.

And, just in the past couple of months, it has started to not like to downshift properly and jump in/out of 2nd during downshifting- no problems with the other gears when driving with the trans selector in D.

I know there is alot of info here and it may end up being easier to just replace. But, I like to properly diagnose something and correct the issue instead of blanket fixing something. Any transmission place I've been to just says, oh yeah, needs a complete rebuild- new clutches, new tq, new solenoids, new etc, new everything. And while this may be the smarter thing for them to do while they have it apart, it appears to me that they lack the diagnostic skills to determine what is bad. If they were to say, this is bad but, I'd suggest doing this as well.. That would be a different story.

I've been driving some of my other vehicles and have been focused on the corvette lately, but really want to have this back up to driving standards for the paint/body work to begin this winter.

Thanks for taking the time to read and for any diagnostic suggestions. I have downloaded and printed this 4t60e information to help with my understanding:
http://www.gmforum.com/howto/transmi...60e/4T60-E.pdf