It is sad to see such a superb model end up this way. The point has been made that the Rx aerial is almost touching the pump. Forget lighting systems, the pump motor is an electrical noise generator!
I don't want to rub salt in the wounds but I cannot honestly think of a worse installation situation. The pump and everything connected to it should be physically separated as much as possible from the Rx and everything connected to it. The only connection between the two systems should be the connection from the ECU to the servo, and this should always have a ferrite ring on it at the Rx end.
This is a challenge in small models but the only way to go IMO.
John