Focus mk2 diesel issues

[Mark D3]

Hi Guys,new to the forum and in desperate need of advice,our 2006 Diesel focus MK2 1.8 tdci is running really rough,like a hunting type noise and cutting out,its been to a garage and they said there was fuel in the tank but not in the filter housing and they had to prime it,they tried putting a new fuel filter in after the problem persists,cars almost un drivable,they have told us to take it to a diesel specialist but due to its age thats going to be financially unviable ,i have read about filter housings going porus,does this affect the mk2?or any other help gratefully received 

[Yungog]

3 hours ago, Mark D3 said:

Hi Guys,new to the forum and in desperate need of advice,our 2006 Diesel focus MK2 1.8 tdci is running really rough,like a hunting type noise and cutting out,its been to a garage and they said there was fuel in the tank but not in the filter housing and they had to prime it,they tried putting a new fuel filter in after the problem persists,cars almost un drivable,they have told us to take it to a diesel specialist but due to its age thats going to be financially unviable ,i have read about filter housings going porus,does this affect the mk2?or any other help gratefully received 

If the filter isn't getting fuel,surely it means there's a problem with the fuel pump? Or there's a blockage in the fuel lines?

[TomsFocus]

These don't have an in-tank pump.  They just rely on suction from the HP pump.  Trouble with this is any small hole will allow air in as the system isn't under pressure.  The only way to find the hole will be to physically look for it unfortunately.

[Dee_82]

and if its a seal that will be easier said than done. but I wonder if the clue is in the empty filter. if its sucking that dry (or leaking from there) then the problem must be at the filter or the supply line. Might be worth looking in to changing the filter housing seals and the seal on the supply line

 

[Dee_82]

also, come to think about it, whilst the sender unit isn't used to pump fuel it is probably capable of pumping fuel, pretty sure its the same part either way, in any case, there is a sock on that sender unit, if that's gunked up with crap then perhaps the HP pump cant overcome the restriction and instead sucks air through a seal 

[FatHead1979]

Having serviced my MK2 1.8 TDCi every year I can confirm that the cylinder type fuel filter is very sensitive on fitting to the rubber sealing ring not being perfectly in place.

@Mark D3 When fitting the filter into the metal housing, there is also flat rubber seal that also needs to be fitted.  Unfortunately the filter design allows the seal to slide around a bit until the housing lid is nice and tight.  Even the tiniest gap in the seal will have the fuel system sucking in air.  This can result in symptoms being as bad as not being able to start the engine at all, through to the engine intermittently stalling due to a build up of air in the system....the latter happened to be when the filter housing lid wasn't quite tight enough to form a perfect seal.

There have been posts on here where even actual garages have not fitted the seal properly (pinched/damaged it when fitting etc).  I reckon it's certainly worth checking.

[Stoney871]

Definitely recommended that a new seal is fitted when doing anything to the filter.
They really don't like being reused or moved about.

Sent from my SM-G965F (S9+)

[Mark D3]

Thanks guys,been to get a genuine filter from Bridgend ford today with a new seal,will check that over,do you lube the o rings with diesel first?and how do you prime it after?

[Tdci-Peter]

2 hours ago, Mark D3 said:

do you lube the o rings with diesel first?and how do you prime it after?

Wetting the o-rings first can help seal it.

The best way to prime these is with a hand pump or priming bulb. Unfortunately quite a lot of the available bulbs are a bit duff. I got one with so much molding flash on the non-return valves that it was almost useless until I carefully smoothed it all off to get some sort of seal.

But if you can get hold of a decent primer, connect it into the line that feeds into the filter. With a good primer, there is no need to pre-fill the filter housing, and it is tricky getting it all together when full of fuel. I tried it once and got covered in diesel. Just open the air vent and pump very slowly until the filter is full, close the vent and pump hard to drive fuel right through into the main pump. This takes quite a bit of pressure, hence the need for a decent primer.

You can also release the filter outlet connector (after cleaning round it), to let remaining air out there. But is is vital to avoid even tiny specks of dirt getting in to the system after the filter. Next stop is the expensive pump, then the injectors. The injectors have some very tiny control orifices in them.

Start the engine. If it stalls, pump some more, then try again. Stop and remove the primer quickly when the engine repeatedly starts and runs ok.

A syringe can also be used to fill the lines, though it and the fuel must be very clean if filling the pipe leaving the filter.

Some people do fill the housing, prime the pipes with a syringe, and then keep starting it until it coughs into life. But even a small amount of air will prevent starting. The main pump can not suck air, at least not at cranking speed. A tow start has been known to work, but is a bit dodgy, and risks running the main pump while dry. I do not really recommend it except as a last resort.

I have fitted a non-return valve to the inlet pipe before the filter on my car. It makes priming easier, and any tiny leaks into the filter should not allow fuel to drain back to the tank, drawing air in.

Pic showing the non-return valve:

 

Pic showing primer bulb connected (not brilliantly clear, but the pipe connector is right at the front of the pic, going to the bulb, then to the top of the filter.)

[Mark D3]

On 28/03/2018 at 12:38 AM, Tdci-Peter said:

Wetting the o-rings first can help seal it.

The best way to prime these is with a hand pump or priming bulb. Unfortunately quite a lot of the available bulbs are a bit duff. I got one with so much molding flash on the non-return valves that it was almost useless until I carefully smoothed it all off to get some sort of seal.

But if you can get hold of a decent primer, connect it into the line that feeds into the filter. With a good primer, there is no need to pre-fill the filter housing, and it is tricky getting it all together when full of fuel. I tried it once and got covered in diesel. Just open the air vent and pump very slowly until the filter is full, close the vent and pump hard to drive fuel right through into the main pump. This takes quite a bit of pressure, hence the need for a decent primer.

You can also release the filter outlet connector (after cleaning round it), to let remaining air out there. But is is vital to avoid even tiny specks of dirt getting in to the system after the filter. Next stop is the expensive pump, then the injectors. The injectors have some very tiny control orifices in them.

Start the engine. If it stalls, pump some more, then try again. Stop and remove the primer quickly when the engine repeatedly starts and runs ok.

A syringe can also be used to fill the lines, though it and the fuel must be very clean if filling the pipe leaving the filter.

Some people do fill the housing, prime the pipes with a syringe, and then keep starting it until it coughs into life. But even a small amount of air will prevent starting. The main pump can not suck air, at least not at cranking speed. A tow start has been known to work, but is a bit dodgy, and risks running the main pump while dry. I do not really recommend it except as a last resort.

I have fitted a non-return valve to the inlet pipe before the filter on my car. It makes priming easier, and any tiny leaks into the filter should not allow fuel to drain back to the tank, drawing air in.

Pic showing the non-return valve:

 

Pic showing primer bulb connected (not brilliantly clear, but the pipe connector is right at the front of the pic, going to the bulb, then to the top of the filter.)

Done exactly what you suggested,got the car running but problems still the same,sadly a new OE filter and i know its all in correctly  hasn't fixed it,i did find this on the recalls on the cars though,does this affect the 1.8?Ford Focus fuel pipe leak (2004-2011 cars)
Cars built between July 2004 and February 2005 could have had problems with their fuel return pipes leaking. The pipes were made from material that degraded over time, allowing fuel to seep out.

[Tdci-Peter]

1 hour ago, Mark D3 said:

problems still the same,sadly

When I first read the original post, I had some doubts about whether it was air in the filter:

" 2006 Diesel focus MK2 1.8 tdci is running really rough,like a hunting type noise and cutting out, "

But the garage saying the filter was low on fuel did point a finger at the filter. What garages say is not always right though!

Rough running and hunting on idle could be a blocked filter, but you have ruled that out too. There could still be air getting in to the pipework between tank and filter, but if the engine re-started quite easily after it cut out, or after standing, then I would be tempted to discount air ingress. Air in the system will always make it hard or impossible to start, and that was not in your symptoms given.

I find it hard to see a link with leaks in the fuel return pipe. That would be a fire hazard, hence the Ford worry, but should not affect the engine.

One cheap, easy test is to try disconnecting the MAF. This is the air flow sensor mounted right on the air filter box. No MAF can be better than a bad MAF, though it should make the engine warning light come on. A code reader to check the code(s) and reset them after the test would be handy.

The problem is quite a lot of stuff can lead to rough running: MAF, MAP, temperature sensors (in MAF, air intake, fuel return and cylinder head), possibly EGR, fuel pump, fuel pressure sensor, IMV, injectors. Oh, and crank sensor!

A diagnostic system capable of reading all codes, and taking real time readings from the various sensors might help eliminate some of these. You can get Forscan (a very sound system) for about £16, but taking and interpreting the data is not everybody's ideal pastime!

An EGR blanking plate is cheap and easy to fit, but major EGR problems usually put a warning light on, so I do not rate that possibility very high.

If you want to try the diagnosis route, I may be able to help, I have looked a few of those signals on my 2006 1.8. But I know that it rarely points directly to a defect, all the signals are rather inter-related. It is more about elimination and clues, like a traditional detective story, but, to most people, rather less exciting than a good Sherlock Holmes book!

 

[Mark D3]

Hi guys,turns out its the injection pump,sadly writing the car off due to its value,we are looking at a petrol focus tomorrow to replace it