We have already replaced the fuel filter following mis-fueling the vehicle. It ran fine for a while, then this problem started to happen. We then replaced the valve and the fuel system was re-calibrated. Again, it ran fine for a week or so, then the engine started cutting out again. Would love your advice.
We don't know which tests to ask the garage to do. The Nissan main agent have just said we need to replace all the fuel lines at a cost of c.£2,500. We aren't convinced that will solve it given that the car runs fine once it is running. We have taken the car to a diagnostics testing centre that spent an hour investigating the poor cold starting fault. 1 code was recorded in memory - P1272 fuel pressure controlvalve malfunction. They recommend removing the fuel pump for checking and testing, but again, that isn't cheap.
They also said that it is possible that misfueling caused some of the metal to chafe and that is still in the system and/or caused damage, but that seems unlikely if it runs OK when warm. Other forums suggest it could be the switch to the pump and we could try disconnecting the battery, leave for 10 minutes, then re-connect. If it starts, then the problem is electrical. We haven't tried this yet.
Thanks so much for your reply. Specifically, what do you suggest we do? What should we ask the garage to do next in order that we can get the car back on the road in a cost effective way?