Auto transmission question

[Buzo]

I feel my tranny downshifts when is not really needed. I would like to ask others with automatic car and see if they have similar performance.

Example 1. Cruising at 55 MPH & 2500 RPM, if I slowly press the pedal for passing, the car will always shift down, and the engine will rev up to 3500 RPM.

Example 2. When reducing speed down to 20 MPH, and try to slowly take off again, the car will downshift too.

It doesn't care how slow I try to accelerate, it always downshifts which I feel uncomfortable.

I can easily mess with the tune of the car so I can avoid it to get too lean when accelerating. So I wouldn't need to press the pedal in excess -therefore pulling the transmission cable too much and causing it to shift-

But before I move my current tune or anything else, I wanted to ask if what I have explained here is just normal. Thanks.

[2oodoor]

Tv cable !
It makes a amazing difference even with just say 5mm travel adjustment.
With you using a gm tbi I certainley would expect some tweak settings.
The placement of the throttle cable bracket to the throttle shaft can limit the adjustment down by the tv lever so if you find that the case you may need to configure that a little.
Reverse thinking about de tuning because the opposite applies as well. The tv mechanism is a primative throttle position sensor for the tranny.

[Dr_Snooz]

Yup. Definitely TV cable.

[Buzo]

By your answers I understand you don't have the same performance as I do.

I'll adjust my TV cable and report back what happens.

I worked with the TV cable at the beginning of my TBI installation because during the first days, the 4th shift was constantly on and off during cruising speed. I stopped adjusting it when I was able to keep it on. But it looks like some more will help with my tranny performance.

Thank you.

[Dr_Snooz]

If you are picky like me, it will take a lot of fine tuning to get the cable just right. Good luck.

[Buzo]

I put hands on into this problem today and the first thing I found is some spring effect in the metal thing that holds the accelerator cable (where the adjusting nuts are). If I press the pedal, it moves like 1/2" towards te carb and springs back when I release it. So its impossible to have a nice adjustment with that kind of play. I will reinforce that piece and start the TV adjustment one more time.

[2oodoor]

Precisely, I had a similar issue last month when I changed carbs from a DGS to a DFAV. The bracket had to be re engineered.
I bet you will be quite pleased with your results.

[ecogabriel]

It is not easy to get the right point one wants; mine is slow to downshift because I over-adjusted the TV cable and I am way too lazy to re-adjust it.
Go slowly (maybe one turn of the nuts per time) and drive it to see if you like what you got
The low speed downshift is normal.