Looking for some advice by you knowledgable bunch. 
 

I have a Ford fiesta 06 1.6 TDCI. 
Car cranks but won’t fire, also won’t fire with jump leads or a bump start. No diagnostic codes on, no signs of pending failures prior to this happening. 
Fuses, relays all tested and all the obvious stuff. 
Skipping to where I’ve got to, fuel line from tank to the filter, had no pressure.

Using a vacuum pump and hoses, I filled the the filter with diesel from a large fuel can and she fired up fine with the fuel line disconnected. 
I was expecting fuel to come squirting out the disconnected line but not a drop. 
Leads me to assume no fuel is getting from the tank to the filter. Now, I’ve read up on the fuel sender units, typically access being under the rear seats. Would a failed sender unit cause this issue, or is this unit purely just to determine fuel levels and doesn’t actually provide any form of pumping? 
Or is this the main diesel pump and is it this that creates the pressure that would draw fuel from the tank?  Is the diesel pump part of the timing assembly on this model? 
 

Thanks! 
 

The tank sender unit contains the 'Lift Pump' in other words the low pressure pump that supplies the diesel through to the main high pressure pump at the engine.

http://www.catcar.info/ford/?lang=en&l=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%3D

No lift pump on these.  

High pressure pump is driven by the cambelt.  But it relies on a syphon effect to pull fuel up and hold it overnight.

Even the smallest crack or pinhole leak will allow air in and cause the fuel to drain back to the tank when switched off.

1 hour ago, TomsFocus said:

No lift pump on these.

Are sure Tom ? There is a lift pump part number for this model. You know a lot more about the fuel system on these than I do, so I expect you're correct 👍

Thanks for the quick info lads.

 Looks like next job is looking for leaks, no real evidence on the drive.

Feel free to jump in if anyone has any tips. 

 Hopefully not the high pressure pump but can imagine that will be the case. 😫

12 hours ago, unofix said:

Are sure Tom ? There is a lift pump part number for this model. You know a lot more about the fuel system on these than I do, so I expect you're correct 👍

Yes, it's a bit confusing as there is actually a pump fitted, it's just not used! 

None of the 1.4 or 1.6 TDCIs used a lift pump between 2004 and approx 2014.  The 1.5 TDCI uses a lift pump and was fitted from 2014.  I have read that some of the very last 1.6 TDCIs may have used a lift pump, although I am sceptical about that, seems more likely that a garage saw a pump fitted and charged the customer to change it.

12 hours ago, Pricey19930 said:

 Looks like next job is looking for leaks, no real evidence on the drive.

There won't be any evidence on the drive, or anywhere else usually.  These leaks generally only allow air in.  They don't allow fuel out because the fuel is not pressurised at all before the high pressure pump.  Makes it a right pain to find the leaks!