Final answer:
After turning the ENG SHUTOFF SWITCH on, the normal fuel flow you should see is around 600 to 800 pph. You should stop the start once the fuel flow reaches idle fuel flow, which is around 300 to 400 pph.
Step-by-step explanation:
After turning the ENG SHUTOFF SWITCH on, you should see a normal fuel flow of around 600 to 800 pounds per hour (pph) for a typical jet engine. This is the amount of fuel being supplied to the engine to sustain combustion.
When starting the engine, you should stop the start once the fuel flow stabilizes and reaches a value called idle fuel flow, which is around 300 to 400 pph. This is the minimum amount of fuel required to maintain the engine running at idle speed.
It's important to note that fuel flow values may vary depending on the specific aircraft and engine model, so always consult the aircraft's operating manual or the manufacturer's instructions for the exact fuel flow values.