A couple of months ago I posted a problem with my Focus 2.0 TDCi. This is just a follow-up in case anyone with similar problems wants to know the outcome.
The symptoms were that the engine would often start and die immediately. It would start and run fine on the second attempt. Apart from that, the engine ran perfectly. I initially thought the starter wasn't getting the revs up sufficiently and a battery test showed the voltage slightly down at 12.4 volts. The battery was 5 years old so I replaced it even though I wasn't convinced it was the problem........ and it wasn't.
Looking at the engine when it was running, I noticed air bubbles in the line from the fuel filter to the diesel injection pump. About every 30 seconds I would get a rush of bubbles. I was sure that this was the problem. I thought the air leak might be from the filter housing so I fitted a new filter and seal for the housing. This didn't make any difference.
I thought the air leak may have been from the fuel pick up/fuel pump in the tank but I wanted to try and pin it down. I don't mind paying to have problems fixed but I didn't want to pay a load of money on fault diagnosis which may be inclusive. I tried to get in touch with a friend of a friend who is a Ford technician but while I waited for him to get in touch, I noticed the problem had stopped and two months down the line has not reoccurred.
I'm pretty sure I now know what the problem was. At the time I was working a 3 month contract and filling up at a service station away from home. During this 3 months, I filled up exclusively at this Shell place (on the A11 near Attleborough). I am now convinced that the problem was contaminated fuel. What I thought was air bubbles I now believe to be water and I reckon that would explain the starting problems. The problems stopped when I stopped using that filling station.