Hi,

ford Mondeo diesl 2.0 litre 115bhp

My car was running for around 5 minutes the other morning and all of a sudden cut out and now will no longer start, the RAC have had 2 hours on it and said it is air locked but advice from a mechanic says its the fuel pump. I have read on the internet it possibly has another pump near the fuel tank Is this correct?? Also the RAC said hes quite adamant the fuel pump was fine and that it had run out of fuel and was airlocked and he said the fuel filter was not filling up so that's why it wouldnt stay running as he manually pumped diesel into the filter and it ran but then cut out.

Advice welcome otherwise its a scrapper.

Can you hear the in tank pump priming when you light the glow plugs? If you can then make sure the pressure is ok at the high pressure pump.

 

I highly suspect there will be a few trouble codes to go from. Get it on a diagnostic machine and report back with codes.

 

I'm not sure these do have a tank lift pump.  The newer diesels don't but I'm having a mental block as to whether the Mk3s did or not!

If not, you'll have a minor air leak in the fuel system somewhere.  It allows the fuel to drain back to the tank and the HP pump alone can't suck the fuel all the way back up.

Is it very low on fuel or is there still plenty in the tank?

MK3's do not have a lift pump in the fuel tank just the one at the engine.

6 minutes ago, pragmatix said:

MK3's do not have a lift pump in the fuel tank just the one at the engine.

Thanks for confirming that.  Looks like either it's just run out of fuel if tank level very low, or an air leak somewhere between tank and HP pump.  

As above, the Delphi  pump is in 2 parts, the low pressure side called a transfer pump, and the hp side that squirts out >1000 bar to the injectors. Most likely cause is a faulty O ring on the leak-off pipes, which results in air getting in and causing an air lock... been there,  had that problem. If they all prove to be sound tho'  and all the other O rings are OK, then.. maybe is the pump! I'm actually in a similar situation, where I recently replaced my pump for a recon one, and I'm finding that the engine runs fine until the filter is empty, and it's just not drawing any fuel from the tank. I'm in the process of refitting the old pump as I think I've exhausted all other causes. If you want the part number of the correct O rings for the leak off pipes, I can  let you have it.