Hello friend ...
have you say. 1. K loses power.
2. The engine is stopped
3. The light lights are set on
a simple test to detect if it would be a fuel pump
is collokar a voltimeter in the pump feed as two + and - cable only. It is not complicated Colokar.
At the time of k I throw your fault. See the voltimeter if the feed is really cut. if so then the pump's stream ...