Just bought a 1991 740 Wgn with 190K on it, runs good but when you accelerate the A/C quits and comes back when you let off. Also, the transmission (AUTO) won't downshift sometimes. Are these related? Does the trans use vacuum for the kickdown, any help would be appreciated.

 

No the trans doesn't use Vaccum. Check the kick down cable by the throttle assembly.

The Vaccum problem look for a small hose coming from inside of the car to outside under the hood.
It will go to the Intake manifold. It will run through a Valve.. Most of the time the Valve goes bad and will cause that.

 

My 91 740 turbo wagon with 191k is doing the exact same thing! Was there a fix?

 

Might want to look at the date of this post and hit the last post button at the top of the page.