Aussiepie

So I own an automatic 95 mustang and i've had it for about 4 or 5 years and have always had troubles with it.
2 years ago i had a full new transmission put into the mustang and the car started running alright, a little better than how it was running but...
My most recent issue is that when i start the car the car starts but then it goes below 1 rpm and will ocassionally go up and down if i push down on the accelerator, but if i don't accelerate the car will just die. Then when i turn it on again it starts up fine, but after i reverse out of my parking spot (just fine no troubles) and put it in drive, the cars rpms drop again. My car won't go over 20 mph for about 5 minutes. I can rev the rpms, but the car always pops a few times on it's way to getting to even 30 mph. Once my car is running for about 5 to 10 minutes, the car runs fine, but i when i start going on the freeway i press the gas pedal all the way down, but won't speed up at a constant rate, the rpms jump past 3 or 4 and the car won't speed up with it.

backlash1

It seems you may have more than one problem. From what you describe, if your gearbox is not low on oil, you may have a slipping forward clutch. So first of all check your gearbox oil level and get under the car to look for possible leaks and if these are ok then you may want to consider having the clutches re adjusted or replaced. The start/stall problem is not gearbox but engine related and will take more info to diagnose properly (ie engine light on or off, trouble codes,happens hot or cold, etc) but you can always start with the basics : air and fuel filters and fuel pump pressure check or inspect throttle body and idle control valve for carbon build up. Hope this helps, cheers
marc