Hi all
Got an Astra van in at the moment, cuts out fault codes for P0251 spill valve malfunction[injection pump]. Cuts out mainly when warm. Looked in archieves mainly fault for fuel pump control unit. Ive had a couple of these with the main engine ecu at fault, the way I found them I had a donor car in at the time. When the fault occurs there's no switched earth from the engine ecu to the spill valve relay. Tested to confirm, my question is have I got an engine ecu fault or is the ecu switching the earth off as a result from a faulty pump ecu? Does anybody know how to test to confirm?

Kind regards
Jamie