Works great and powerful if I put it in gear right after I start it. If I do it that way both reverse works and drive. But if I remove it from one of the two. It WILL NOT go back into gear. Also, if I wait even 10th seconds before I put it in gear, it won't go. Tranny fluid is due for filter and fluid change. But sometimes, if I put it in year quickly and go, after I drive a bit, timing has always been different, it will "fall" out of gear. And then it won't even use first or reverse until I shut it off, restart and quickly shift. Transmission is 700r4 and was recently installed. I read there are vacuum lines? wiring Connector is in and works. I'm lost. Why it would engage now and not later. When shifting right, it shifts smooth and good. Thanks in advance guys.

350 in a 84 trans am. 700r4 tranny. Neither of the two came with this car. stock everything else.

 

Replace the clutch kit.

 

There are no vacuum lines to a 700R4 tranny.