Hi not sure if anyone can help but I'll ask anyways. I have a Ford focus mk3.5 face-lift 1.6l diesel tdci 15 plate. I was driving down the m1 and the car beeped and said service engine then started slowing down once it hit zero the engine stopped and wont start. I've noticed I can't hear a hum coming from the fuel sender unit under the back seat and I have no fuel coming from the fuel pipe to filter when trying to start it. I've hand primed and fuel comes out so no blocked pipes I've changed the fuel sender unit and still nothing I've recently taken it the a garage who did a compression test and said there's only strong compression on 1 cylinder and would be cheaper to replace engine but never mentioned a fuel problem. Could this cause the fuel pump not to work or is there something else going on any help is  appreciated thanks

The major issue IMHO is the possible lack of compression which needs to be confirmed, witnessed and investigated.
Need to narrow it down to valves  or rings/bores.

If it's valves it may mean a cylinder head job otherwise it's really major engine work.

What about cambelt/valve timing - has that gone out - when was that changed?
Add tablespoon  of oil and repeat the test, if compression improves, it's rings - the oil seals them temporarily?

In any case it looks serious but will need to be certain.

The fuel issue may well be separate but that would need to be checked by activating the lift pump or removing and testing to see if it supplying fuel then looking at high pressure pump?

At the moment, it's all very nebulous and difficult to be certain?

If this is a 1.6 TDCI then it doesn't need an electric pump in the tank.

Most facelifts were 1.5 TDCI which do use an electric pump.

Try some EasyStart down the intake.  If it runs on EasyStart then look further into the fuelling.  If it doesn't run in EasyStart then it'll be an internal fault.

@Shearers im happy to replace the engine as it's going to be costly to repair. It's more the fuel issue I'm looking into and curious about. The sender unit under the rear seat i was able to hear i believe. It's when we disconnect the fuel pipe to filter and try to start no fuel comes out which makes me think the fuel pump on the engine isn't working my main question was is there anything in the engine that could switch the fuel pump off as when we're tested the fuse for the pump we get no power on the multi meter. I'm starting to think if the answer is no to the engine switching the power off for pump then the high pressure pump on the engine is knackered. I will be honest I have in the past ran it with no fuel till it was juddering twice which I know won't have helped .

@TomsFocus yes this is the 1.6 tdci loads of people have tried the easy start method which is probably why my engine is more knackered. 

4 minutes ago, Ford Mark1 said:

@TomsFocus yes this is the 1.6 tdci loads of people have tried the easy start method which is probably why my engine is more knackered. 

Did it run or not?

If you want to rule out the tank pump, run a temporary permanent 12v feed directly to it.  But I'm almost certain it isn't needed on this car anyway, which is also confirmed by the fact there's no power to the fuse.  On cars that do use the tank pump, it gets primed as soon as the ignition is switched on, there's nothing on the engine to prevent it working at that point.

13 minutes ago, TomsFocus said:

@TomsFocus no every time easy start was used nothing happened the thing is the car sounds like it wants to start but won't. Ive had 3 different sender units on and no noise like I think there was before. It's just strange that no fuel is being pumped when the engine is trying to start. I could replace the engine and still have a fuel problem that's what I'm trying to sort of before I replacing  my engine as I've found one. So if there's nothing int he engine that won't cut of the power to the fuel pump then it's got to be the high pressure pump or electrical. It just baffling which out getting someone to full on stripp the car down.

 

The HP pump sucks up the fuel.  Fuel doesn't need to be pumped from the tank as long as it's been fully primed using a handpump first and there are no air leaks in the system.

The vast majority of 1.6 TDCI's don't power the tank pump (MK2, 2.5 and Mk3 Focus) though I can't say for sure whether the facelifts do or not.

If you're replacing the full engine then that'll presumably come with a HP pump anyway, so it doesn't matter if that's faulty.  And unless that's also come from a Mk3 facelift, then I can confirm that it won't need a tank pump either.

The low pressure fuel system is very simple, so if you are going to replace the engine, then I wouldn't worry about that until afterwards.  Either it doesn't need the fuel to be pumped in the low pressure side.  Or if it does then you can easily bypass it in the short term by running a temporary 12v feed to the pump.

What I would recommend is removing the fuel filter and checking it for brass filings inside.  Those come from the HP pump if that's worn out, and they go on to damage the injector and the new HP pump.  The full fuel system including the tank would need to be flushed out if any filings are found in it.