well this is kind of weird because i replaced the tranny on my grand am and after that i started having issues with the car acting and shifting weird, it would shift good 1-3 and when it would shift to 4th it would shift really hard and after that when i would come to a stop and take off, all the gears would shift hard. I looked at all the possibilities that would make the tranny do this and it wasnt the IAT or the TPS, turns out that the purge valve for my car was going bad but funny thing is that how would this affect the way my tranny shifts...... well it turns out that after i traced the wires from it and looked at the wire schematics the purge valve is connected to the tranny , why i dont know, but i got a new one and also i remembered that before i had the HO manifold the purge valve only saw vaccume when the throttle body open not vaccume all the time like how most of us have it hooked up to the HO manifold.

On the HO manifold usually people hook it up right next to the fuel regulator port, well this thing its not supost to see that much vacume you have to have it hooked up before the throttle not after the throttle. So anyways i replaced the purge valve and move the hose to the throttle body and now is fine. I tought this was weird, but this is not on a jbody this is on a Nbody so i dont know if it will do the same on a jbody since is the same motor.


http://a709.ac-images.myspacecdn.com/images01/85/l_c45bfa9c54e0aebaf0fbf6bf67c30a74.jpg

prehaps a diffrent gear ratio and the ecm is not happy with it

yeah i forgot to add that the tranny i got for my 99 grand am came from a 99 cavalier, would that cause it to shift hard, is there a difference between the cavalier tranny and the grand am tranny?


http://a709.ac-images.myspacecdn.com/images01/85/l_c45bfa9c54e0aebaf0fbf6bf67c30a74.jpg