Ok, so I´m having this problem with a 2008 Ford Mondeo mk4 with a 2.0 TDci engine code AZBA, same one Peugeot uses in other cars such as the 407. Car was having trouble a few days back to start whenever it reached normal operating temperature and it was stopped. It took like 10 seconds cranking to get it started. So I started plugging in my OBD scanner which throw me a p0087 error, low pressure on rail. It wasn't present, so I deleted it and performed an adaptation reseting all systems. Furthermore, I found out that three of the injectors were leaking like crazy, so I proceed to check it closely enough to find out they were losen, so I tighten them a little bit more. The issue kind of disappeared for a few days, but now I´m having the same problem again, only I have not leakage and fault p0087 is now present, oh, and it doesn't start at all, doesn't matter if it´s cold or hot. So I decided to test bypassing the whole low pressure system and putting it some diesel directly into the common rail high pressure pump, and yes, it started right away. Now I´m thinking but I´m not sure and that´s where I need help, that probably some kind of lift pump is broken, and if so where is it located, cause I haven't been able to find it close to the tank. Could it be that this lift pump is integrated with the high pressure pump?
I just find out today after bleeding all the left air in the low-high pressure sides, that it wasn´t the lift pump that was faulty, but just a rubber seal located on the entrance to the high pressure pump. It took me quite a long time to find out but after discarding there wasn´t any kind of lift pump located on the fuel tank (Mondeo MK3 does have one there), and that it was indeed integrated among the common rail pump like other PSA engines usually do. I replaced this rubber seal and now car works like a charm with 270000 Km. If this same failure still persists in the future, I´ll just install a non-return valve close to the high pressure pump, and a small gasoline pump that helps send the fuel along the fuel lines because it does make the difference on this particular case. Regards!