The fuel control of the Allison 250 series engine controls the temps during start...not the fuel nozzle..
The engine output is controlled in two normal stages by the pilot. First, the engine must be started and increased to a speed range where the power turbine governor has control. This is accomplished by actuation of the gas producer fuel control throttle lever through the airframe control linkage which ends at the twist grip.
The throttle twist grip has three basic positions: CUT OFF, IDLE, and FULL OPEN. When the twist grip is moved from the CUT OFF to IDLE during engine starting, the gas producer fuel control automatically meters fuel as a function of compressor discharge air sense and N1 rpm.
Engine light off, acceleration, and idle stabilization are a function of the gas producer fuel control only.