This can happen because of a LEAN condition.

The engine is leaned out because of the nose up attitude, then when you pull back the idle speed setting of the needle does not supply enough fuel to keep the engine running.

I would start by richening the idle four clicks and doing a nose up test AT IDLE.

Then richen the HS needle one or two clicks and with the nose up, run the throttle up and down, to see if you've cured the problem.