how to fix fuil rail on renult master van 2046cc gtmac?

Unlikely to be anything wrong with the rail itself but would check out the sensors/fuel regulator valve on the rail itself. You really need a good diagnostic computer/code reader to have a look to see what each is doing when the motor is running. If it`s not running then you will need to check what pressure is there under cranking.

cdc
April 2016