Ok so I just got done putting in my freshly supercharged l26 in my 2001 Monte Carlo. I took out the tranny with my engine and of course lost some fluids so before I got the car running I put some more tranny fluid in it(only about a quart). Then I started it up and tried driving it. Well when I went to drive the engine would rev but the car would barely move. So i didn't get very far and I checked the dipstick and couldn't get an accurate reading so I put about half a quart, maybe a little more, and would run the car again to see how it drove and repeated that until I had put about a gallon plus half a quart in it and it's driving better now but still won't shift for crap. When I try to drive the car the engine bay will get VERY VERY hot but the engine temps seem to be good.

I'm assuming I just need to put more fluid in it but I did NOT think I lost that much fluid when I pulled the tranny out but I'm probably wrong and just forgot how much I lost. Aside from it not shifting for crap my concern is if I have any major damage done to my transmission by running it with fluid so low that it would barely drive then slowing adding more in it and driving it again.

I also don't know if it hurts things but I tried using shift lever to put it in 1st 2nd and 3rd bc it wasn't shifting when I wanted to and the shifts are loooonnnngggg!
I don't know much of anything about transmissions so if any has some advice I would really appreciate it. Thanks

 

are you using the stock transmission from your car or the one from the donor car?

which PCM file are you using?

make sure the transmission electrical connection is seated fully and make sure all the grounds are secure (there are at least 2 that connect to the bellhousing bolt) and another near the coil packs.

if you pulled the tranny, you could have lost a lot of fluid when jerking it around to break it free from anything that it could have gotton snagged on.

but a gallon of fluid, plus another qt (5 qts) seems a bit excessive. a pan drop with a filter change only takes ~8qts.

if it was in fact that low, unless you went driving like a dumb ***, it shouldnt have damaged anything.

my hunch is something isnt connected right (electrical as mentioned above) or mechanical (make sure the gear selection arm is installed correctly) or something is wrong with the PCM tune you have.

 

A lot of what I read sounds like incorrect trans fluid level. If you are low on fluid, it's harder to build up the line pressure required to shift gears.
Confirm your fluid level is correct and that you are not leaking trans fluid.

 

Ok so I didn't see the second ground that connects to the tranny so I hooked that up and now the fans are running so that's good but the transmission is still have troubles. I've put quite a bit of fluid in it so that shouldn't be the problem anymore. The shifts are pretty smooth but seem a bit long.

And I was using a zzp pre programmed pcm but i put the stock pcm back in bc it honestly seems to run better with the stock one.

And I no longer have a check engine light on.