1991 Pontiac Sunbird 160,000 miles automatic transmission.

I asked this question the other day, but there is a little more to it now. The car sat for about a year due to a timing belt issue. I have changed the timing belt. Since then I have slowly had more and more trouble with the way it runs. The acceleration is slow-it takes it forever to go from a complete stop and is now trying to stall out. It backfires sometimes and it at times seems it's not getting any gas. I'm trying a tune up and oil change done tomorrow. Aside from that what else can I do to improve the way it's running? There is also a whine that sounds like it's coming from the transmission when i'm stepping on the gas, and it's slow to go. Once it shifts gears it goes fine. Also it seems to do better once I get it past 40 before 40 it runs really bad.

Just sluggish. It feels almost at times like it's not getting any gas, but at the same time it could go two city blocks before I can get it past 20-25. It's rather annoying.

No, I haven't gotten that far yet, how many are there and where are they

I bought a Sunbird yesterday and it is doing the same thing, aside from that mine, needs about 1-2 quarts of transmission fluid per-day. I am not sure as to why it is doing this, I am definitly going to try replacing all the puel filters tomorrow though. If you have found out how to make yours go like it is supposed to, you should write it on here and let me know what else to try!

Thanks in advance!

Lady Machia Karee