I have a stock '89 with the 700R4. My problem is under normal acceleration it seems to shift into 2nd and 3rd gear rather quickly (shifts into 2nd around 9-11 mph) and doesn't always downshift at WOT from a roll. Is this a TV cable issue?

Matt

 

Sounds like it.
Cables DO stretch and these tend to have the end caps rot and break off giving the cable another 1/2" of slack...so the trans starts upshifting too soon and the "passing gear" downshift disappears. Mine did that and I could floor it under certain conditions and all it would do was bog. No attempt at a downshift. Re-adjust the TV cable...good as new. The little dust cap/seal on the cable sleeve had fallen off giving it slack.
Adjust the cable and observe the differences. If it fails to stretch the upshift...its a valve body problem. Not a huge deal, but enough that a crooked tranny shop could use to con someone into a rebuild or replacement trans for BIG bucks. If you feel like it is internal and needs shop service,. find someone thru friends or the local Vette club. Trans are witch-craft to most folks and shops know that and take full advantage of that and sell trannys or rebuilds that are not needed.
Its plain shocking what the big box trans shops get for that transmission these days.

Pull 1/4" more tension on the TV cable and test drive. Remember that if its left in 3rd the TCC will lock in the converter and hold it until you touch the brake, then the TCC releases the trans.
If you drive away in 4th (OD) that defeats the TCC and it will seem softer and the converter will release sooner. Driving in 3rd gives more of a 'stick' feel while 4th gives that auto-trans feel of smoother shifts and early release. The TCC just manages lock-up or not.

The proper cable adjustment is an upshift to 4th OD at approx 55 mph.
If its shifting into 4th below 50 its set too low. Some folks are doing that intentionally trying to get the most mpg that they can by cruising at a low rpm even though its a little hard on the engine towing around a 2 ton car at 13-1400 rpm....Of course it comes down to final drive ratios, but the lowest rpm IMO that an OD gear should see is around 16-1700, where there is enough torque being generated to handle the load. Torque= turning effort. HP=strenght or ability to maintain against resistance.

 

Thanks! I just readjusted the cable and drove the car. The gears felt more stretched out and it didn't shift into OD until 55. Passing gear is back too!