I have a 2005 Ford Fiesta Zetec Tdci 1399cc.

Shortly after buying it as a used car in 2010 I had starting problems.

The car would start on the first turn of the key run for a few seconds then stop and would not start again.

The first time this happened I called out the RAC and they diagnosed air in the fuel line. The attending engineer primed the engine - there is a rubber bulb to the left of the engine which he squeezed for quite a while - then the car started.

The local dealer where I purchased the car wasn't interested so I took the car to the local Ford garage. They eventually diagnosed a 'pinched O-ring in one of the intake pipes to the fuel injector'.

This seemed to do the trick. The car ran without any further starting problems - until recently.

A couple of weeks ago exactly the same thing happened on start up. I called the RAC again. I explained to the engineer that I had the car serviced at a local garage that week. The engineer diagnosed air leakage in the fuel filter. Again, the car started after priming.

I took the car back to the local garage that I had been using for repairs, servicing and MOT and they looked at all the possible causes. They even drained the fuel to try and get rid of any air locks.

The car started OK for two or three days but over the last few days the same problem has occurred.

It's not a critical problem since I know how to get it started (by priming it) but I am concerned that by continually having to prime it I might damage the rubber bulb.

Is there anyone out there who has had a similar problem and can point me in the right direction to solving it permanently?

To be honest you should not consider it normal to have to prime the system so often.

When was the fuel filter last replaced