Friend's 86.5 n/a Auto won't stay on

[SupraStoked]

My friend's immaculate 86.5 supra auto n/a won't stay on when it's shifted in to Drive or Reverse. In neutral it stays on and idles perfectly though. His engine is not misfiring, leaking, or anything like that. His car really is a gem all around except for this problem.

I'm not too familiar with auto transmissions but this might have something to do with the problem...every time he shift into drive, the car jerks forward pretty hard.

His battery is showing 12 v...well at least the idiot gauge is. His battery is pretty small compared to the battery I have in my 86.5.. Anyone know what his problem might be?

 

[hvyman]

Is the car stalling out like when you forget to push the clutch in or take it out of gear in a manual?

 

[supra_lover]

the car idles around 600,700 RPM and the needle bounces, the engine is revving in sync with the needle, so its a repeated pattern, this was when the car was parked... the car needs to be put into neutral to keep the RPMs above 1000 on the street lights, or else the needle slowly drops, the car shakes, and then turns off. acceleration hasn't been smooth lately either.

 

[Nick M]

Can he drive it if he puts it in drive and steps on it quickly? If so, look to see if the torque converter is locked.