ive notice that if my car sits overnight and when its cold i have to warm my car up before i start to drive it becuase it wont shift after first gear, once the car is all warmed up it shifts fine with no problems at all, its just when the car is cold it wont shift after first gear? what could the problem be? would a bad vacuum modulator cause this problem? i just dont like waiting for the car to warm up its takes to much time, i just want to go in fire it up let it idle for a few secs and drive off

You shouldn't have to, and a modulator wouldn't have anything to do with that I don't think. Sound'* like somethiing a lil more complicated. What are the temps where you are?

And how many miles on the trans? Is it original, or rebuilt? Ever had it flushed or changed the filter?

Can you update your signature with your year and trim level in your profile, and add your location?

i believe the trans is orginal it has 192,000 miles on it, i did replace the filter and the fluids last month, i also added some lucus trans additive and i live the the suburbs of chicago and the temps here is about 20 degrees.




1995 bonneville se model

I live in the same climate basically and don't ever have that problem....But that additive kinda makes me wonder because I know that stuff is thick. Why did you use the additive?

i had this same probem since i bought the car, so i changed the fluid and the filter and i thought this lucas additive would help it and yes this stuff is a little thick, ive heard many people saying that lucus products are good stuff to use



1995 bonneville se model, 192,000 miles

i dont have that issue

Neither do I. But, I do let the car idle for a minute [when cold] before driving, and I don't even think of going above 2.5-3k rpm before the car is up to operating temp.


-justin

You all wont belive this but i did this one time. I stated my car up because I was running late for work and just took off. 35* out and I drove kinda fast. When I got to 46 mph, the torque converter lock up thingy worked. I though the car had to be watmed up for that, but it went through all 4 gears and the OD. I was surprised.

Don, I like the weak pump theory. Makes sense in the cold until the fluid warms the pump up a bit.

If you get a professional flush, they'll tell you your pump pressure. At least one style of flushing will.

The lucas products are fine for trans use. I've done it, and it helped the issue I had, but the thickness of that viscosity (VERY thick stuff) can't be helping your issue.