Fuel related issue on rear engine

[n86121]

Works HOT, COLD, and in between.
Even heat soaked engine.

STEPS
1. Throttles CLOSED
2. Props FORWARD
3. Mixtures RICH

4. Boost pump HIGH -

5. Throttles - move from CLOSED to OPEN then CLOSED again - about 3-4 secs for cycle
Pushes slug into injection system of fresh cool fuel under pressure

6. Boost pump OFF

7. While starting, slowly move throttles FORWARD until it fires (every time)

My theory is it puts a slug of cold fresh fuel into injections system