alright right im trying to find out what the problem is i have a 95 z28 its an automatic with a rebuilt engine, so when i turn the car on it is fine in park and then i put it into first and it bogs down like its in a higher gear, but if i move to the 1 on the shifter and then hit the gas it slowly go's and also if im in one the shift to second nuthing happens. then when i shift into drive it shifts down, also if i leave it in drive it backfires and starts of slow and never shifts up even at higher speeds. So my quesiton is whats wrong how do i fix it?

 

You first need to scan the car, And see what if any codes are present , That would be my first move