Hi there, I apologize if this is too similar to another question already on this forum. I did indeed look all over but never found one that matched what happens quite like mine.

I'll try to explain the best I can. I'll write out a list in case I don't explain it good enough.

At Highway speeds (To get to my job I must take the interstate for about 80 miles per day) it will want to shift between Overdrive to Drive, then immediately back into OD. It mostly does it when I barely touch the accelerator while cruising at 65-70mph with no change in load or elevation. It will also shift up and down when it hits a gust of headwind or multiple times in certain ranges. Sometimes it acts that way out of the blue at higher speeds where it just goes up & down & up & down..... you get the picture. Now if I give it more juice rather than a small bit of accelerator movement it stays in OD and the up & down shifting doesn't occur. That's about as good as I know how to put it.

Info & Symptoms:
-1992 Camaro RS 35th Annv. Edition 3.1 V6 700R4 Auto
-160,000+ Miles
-Completely Stock / No mods
-Wants to shift up and down between OD and D at highway speeds 50-75+ mph
-Occurs with slightest change in accelerator depression, gust of wind, and sometimes randomly at about 65mph. It then goes up and down, over and over until I change how far down I have the Accelerator pressed.
-OD @ 65-70mph is about 2500 rpm. When it shifts down into "D" it jumps to 2750-2900 rmp, then immedialty goes back into OD.
-Mainly Occurs during "Cruising speed".
-No other issue with gears acting this way
-Give it more than a slight depression on the accelerator and it will stay in OD and wont shift up and down.
-Started a a while back and keeps getting worse. (I first thought it was just having trouble getting up to speed with the a tired 3.1 powering it, but that's obviously not the case.

I don't want to damage the transmission so I'm kinda nervous here. Any help, suggestions, etc is much appreciated. Thank you in advance. I am sorry it's kinda a lot of a long winded question to ask people to read but I am stumped.
CodyJ

 

have you tried readusting the tv cable?

 

No unfortunately I haven't. I guess I am a bit nervous to do so. I hear if you get it wrong it can burn up the transmission. Then again, malfunctioning isn't much better. I'll youtube it and watch how to do it.

Thanks!

Cody J

 

the newer 700r4 is a bit tougher when it comes to converter lockup. thats usually what burns things. its not very hard you just want it tight at wot. if its to tight it will kick down like what your seeing. i was kinda nervous the first time it did it on my old 92 pickup.

 

Thanks Craby! I will do that this weekend. I need to change the Fluid and filter too. Looks pretty old but doesn't smell burnt or look too bad other than that. So that's a plus I suppose.

It also has another issue that it has had since I got it. At only Idle in "D" at a stop the revs will go up and down. From 1200rpm (Which seems high just sitting) then will drop to about 700... choke and almost die, and jump back up to 1200. After a while it will flash "Service Engine Soon" fairly and gives me the TPS code. So I replaced it. Runs great then a few months, then later it begins again.

I have replaced the Idle Intake Valve, EGR (which was taken off when I got it) and checked all the vacuum lines and seals near and around the intake. Still gives me grief. I also got an AC Delco TPS and it really didn't like that one at all. The movement it the AC Delco was really stiff and it went all haywire on the interstate. Long story short, it involved getting stuck with the throttle wide open and me having to turn it off and coast to a stop on the highway. I put the old one back on and it quit trying to kill me. Christine situation maybe......?

I'm not very good with any medium-new electronics stuff. Every vehicle I have ever owned has been 1974 and older.