i a 5k in a ke30 and wen i stop at the lights it just dies but if i hit the acclelerator just once its right? fuel issue?

Sounds like it-

 

Does it depend on how hard you stop, or if you just drift up slowly to the lights?

 

Carb... air leak.... idle circuit?

 

If it has a "deceleration slow dashpot" I'd be suspicous of that straight away. It helps emissions by controlling the speed that you can shut the throttle at.

...and I wonder if the brake booster is leaking air in and making it too lean to idle!

+1 on the brake booster vaccuum leak.

+1 vacuum leak