You will have to isolate it to either fuel or air, as it has to be one. Try holding the throttle open when you start it up. This will provide the air, so if it still stalls, it has to be the fuel.
There is another action that could cause it, and that is the spark. When the engine is idleing the speed is set by the Idle air valve, but this unit is slow to react, so the ECU uses the spark setting to quickly change the idle speed till the Idle air valve adjusts its position to hold the new setting.
For instants, if you move the steering wheel the load of the pump will slow the idle speed down. To prevent the stall the ECU advances the spark, this picks the idle speed up instantly, once the Idle air valve has opened the hold the speed the spark goes back to normal. When you stop turning the wheel, the loan comes off, the ECU will retard the spark to drop the idle speed, till the Idle air valve takes over.
May be your Idle air valve is too slow to react, and misses the pick-up time.
Harvey.
