Stall while breaking

[verb.zero]

So ive had this 87 TII for a little while now my T13b doesnt have a cold start or BAC so i have to baby it till warm up. The motor does have a street port with super seals, but every once in awhile when im stopping the motor will do its normal bouncing idle then sputter out... my idle is roughly 900 and jumps from that to 1200 rpms. I thought it would be vacuum leaks so i borrowed a buddies leak tester and checked everything i only have a small leak at the intake from the nonstock intercooler adapter for intake is. Any ideas what could be causing the car to stall when stopping?

[vrracing]

See if the ECU is detecting when you press in the clutch or put the tranny in neutral.

And get a BAC! :-)