Just purchased a 2007 1.8 TDCi Zetec Focus (39500 miles on clock) and during my first 3 months of ownership I`ve had 3 occurrences of an issue which is proving difficult to pinpoint a solution.

The situation:

After coming off of a motorway/dual carriageway after a long period of higher speed driving (legal obviously) and stopping at a roundabout/junction, the car simply stalls and will not restart. It just dies and attempts to restart fail with what feels like no guts/fuel/spark when the engine is cranked.

After a few attempts the dashboard info-panel reads “Engine system fault” but not error codes are recorded and the starter motor still cranks but no life.

In two of the occurrences, I left the car to sit for 5 minutes and then retried with success although it was a strained explosion into life and not how it usually starts. On the third occurrence, I called the AA who towed me to a lay-by, by which time the car started with a plume of black smoke from the exhaust. The AA diagnostic showed no fault codes and all engine temps/rpm/fuel pressures were normal. The AA speculated that the fuel sensor/fuel system was at fault and highlighted a plug connector on the fuel sensor which may have not been sending signals to the management system.

The car has been fully serviced from new and in all 3 occurrences, the fuel level in the tank was low but not vapours (reading around 70 miles on the range).

The car has been back to the garage that it came from but they could not find anything wrong and explained that without fault codes, there was not much they could do.

Other than these 3 occasions, the car runs very well – averaging 63mpg on motorway, starts first time-every time and is smooth and great to drive.

So, anyone experienced something similar or has any ideas as to what might be causing this infrequent nuisance?

Cheers, James.

It sounds very strange that either the AA or the garage couldn't find any fault. The EGR valve on those diesels are known to act up causing them to smoke a lot and lack power. I would suggest taking matters into your own hands and cleaning it with a can of Wynns EGR 3 cleaner. There is a good video tutorial on youtube showing the procedure. You will need someone to keep the revs up a bit the car whilst you spray it into the valve.

this could be the fuel filter, it all ways a good idea to change this, as they block-up very easy, if you have had some bad fuel..also Check the Air filter as well if it is blocked and the car comes to idle speed the maf sensor could make it stall if it has not got the right amount of air flow passed it, its worth a look.

this could be the fuel filter, it all ways a good idea to change this, as they block-up very easy, if you have had some bad fuel..also Check the Air filter as well if it is blocked and the car comes to idle speed the maf sensor could make it stall if it has not got the right amount of air flow passed it, its worth a look.

I'd agree with the last two posts, but look at the filters mentioned in this post. Filters are always a first port of call, because they are there for a reason but maybe been neglected by previous owners.

Thanks for the tips, just ordered me a Haynes manual (always do this when a car has its 3rd birthday!) so i`ll locate the various suggested areas and have a tinker!

Cheers, James.

Continuing with the investigation, replaced the air and fuel filters as advised and I`ve attached photos of what I found..... not what I was expecting what with x2 Ford service stamps in my book!!!! Never seen an air filter and fuel filter in such a state, surprised the car ran at all! Have ordered some Wynns Diesel injector and EGR cleaners just to make sure of the other possible causes to the original problem.

So now that I`ve disconnected the fuel system, I need to bleed the air out as the car will not start and was wondering what the best/easiest/common way to do this is?

I have exactly the same problem with my C-Max 1.8 Tdci which is June 2007 with 40k miles and 3 mds which I purchased 2 months ago.

The car has been driving really well but has a tendency to cut out easily at junctions. Having recently taken it on 2 long high speed motorway journeys it has cut out both times having just left the motorway on the return journey and has been very difficult to restart. It seems to be a case of leaving the car for 5/10 minutes when it reluctantly restarts. I had to call out the AA last time but cancelled the call once it started.

Always starts first time on a cold start and the car drives beautifully apart from this problem.

Any advice anyone?

Hi Guys,

I've got a Focus 1.8 TDCI with 66k on the clock with the exact same fault. Did anyone get to the bottom of the fault because I'm starting to pull my hair.

It left my wife stranded in the middle of a motorway round about the other day, scared the hell out other and now refuses to drive it (which I don't blame her)

I've replaced the fuel and air filter, run redex throught the fuel system and have blanked off the EGR valve and it still cuts out :-(

Can anyone help please.

Vehical speed sensor???

I would try unplugging your MAF for a while and see if the problem goes. Also just being picky here but diesels are by detenation of the fuel being compressed patrols have a spark to ignite the fuel. No spark for tractor combustion.

A MAF sensor wouldn't stop it from starting tho! If the sensor fails the ECU would revert to base settings.

A MAF sensor wouldn't stop it from starting tho! If the sensor fails the ECU would revert to base settings.

what about if it was passing erroneous data back to the ECU, if its covered in oil the air flow wouldn't cool it so the ECU wouldn't have accurate data,

cleaning my MAF cured a rough idle and gave me an extra half a pound of boost pressure. amazing what a little piece of hot wire can do.

Are you referring to the MAF sensor or the Boost Absoloute Pressure sensor (the small sensor on the metal piping just before it goes into the inlet manifold)?

The MAF sensor shouldn't get anything on it due to all engine breathing pipes etc are after theMAF sensor, but if you mean the BAP sensor then yes it's a very common fault the majority of Diesel engines as that gets covered in moist, carbon/oil from the engines breathing/venting system and yes you should see great results after cleaning it.

I've already had mine out and carb cleaned it.

For the first time today an engine system fault has come up go I plugged in and got P0504, Brake switch A/B correlation. As its a two part brake switch 1st goes to operate the brake lights and 2nd goes to ECU.

Will replace today!

Nope, definitely the MAF, the MAP sensor ive not cleaned but was where I saw the increase on a before and after run.

MAP maxing at 35.8PSI before, cleaned, 36.4PSI.

MAF at idle had fluctuating 8-12 g/s before, steady 10g/s after.

Ill need to give the MAP a clean, I had assumed it wouldn't need it due to how it works but I guess it cant hurt! :)

Cool, well thanks for the heads up. Il pull my MAP sensor out today and give it a clean too 👍

electrical contact cleaner mind!

Sorry, you probably knew that, but for others reading this, don't use carb cleaner etc

Cool, well thanks for the heads up. Il pull my MAP sensor out today and give it a clean too 👍

Ok guys I think I've made a break through!

To the guys that have had the same fault are you still on here?

Can you remember having a service before this cutting out problem started? If so do you remember what service you had, just an oil & oil filter (small service) or a major service oil, air & fuel filters replaced and oil?

If you could get back to me ask I hope you will be able to prove my theory!

Thanks Greg.

I've only had the car a year but it had a full service before I got it so I thought I'd do my own FULL SERVICE on it and paying particular attn to anything on the fuel system and i found that the fuel filter was saturated but not too bad so I would say that it had been replaced prior to me buying it.........BUT..........I found the small O'ring in the fuel filter housing lid deformed where someone has pushed it into the fuel filter without care and pinched the the O'ring out/off of its seal!

My theory is that around town the fuel flow through the filter isn't that great and fluctuates so it's ok but following a steady 70-80mph M/way drive the fuel flow would be steady and flowing at a high rate, thus when pulling up to a round about or lights and eng speed dropped mixed with that O'ring not sealing the fuel flow back to the tank partially sucks/emptys the fuel filter causing negative pressure and cause an air lock type symptom making the engine cut out.

I think the cranking of the eng & allowing the engine to sit for 5-10mins allows the fuel to be drawn back up from the tank thus reversing the effect!

Your thoughts please guys!!??

Once again thank you Greg.

Ok guys I think I've made a break through!

To the guys that have had the same fault are you still on here?

Can you remember having a service before this cutting out problem started? If so do you remember what service you had, just an oil & oil filter (small service) or a major service oil, air & fuel filters replaced and oil?

If you could get back to me ask I hope you will be able to prove my theory!

Thanks Greg.

Hi Greg,

Yes the same problem started in my car after full service. The guy has changed the filters and then bleeded the oil few days on different occasions but still the car wont start after a journey, though it starts first time in the morning. I have noticed that it causes the problem particularly in the sunlight. Any suggestion?

On 07/03/2015 at 9:19 AM, ooGQoo said:

Are you referring to the MAF sensor or the Boost Absoloute Pressure sensor (the small sensor on the metal piping just before it goes into the inlet manifold)?

The MAF sensor shouldn't get anything on it due to all engine breathing pipes etc are after theMAF sensor, but if you mean the BAP sensor then yes it's a very common fault the majority of Diesel engines as that gets covered in moist, carbon/oil from the engines breathing/venting system and yes you should see great results after cleaning it.

I've already had mine out and carb cleaned it.

For the first time today an engine system fault has come up go I plugged in and got P0504, Brake switch A/B correlation. As its a two part brake switch 1st goes to operate the brake lights and 2nd goes to ECU.

Will replace today!

I'm having exact same issue of S-Max 1.8tdci year 2007 cutting out when we slow down typically to come into a motorway toll after having driven at good speed for approx 2 hours. The engine turns over but won't start. Leave it for maybe 10mins and it will start a bit sluggish but will recover to normal on applying a bit of throttle. 

Would be very interested to know if anyone ever got to the bottom of this issue. In particular was ooGQoo's theory about the fuel filter housing o ring ever proven. 

There a fair few reports on this forum and others about difficulties in seating the fuel filter o-ring on the Lynx engine (I had the same problem when I 1st serviced mine).  The seal fitting has to be perfect otherwise the types of issues described about can and often do happen.  As long as car is taken when refitting the filter 'lid', the o-ring shouldn't get pinched.

On ‎16‎/‎03‎/‎2015 at 3:12 PM, ooGQoo said:

I've only had the car a year but it had a full service before I got it so I thought I'd do my own FULL SERVICE on it and paying particular attn to anything on the fuel system and i found that the fuel filter was saturated but not too bad so I would say that it had been replaced prior to me buying it.........BUT..........I found the small O'ring in the fuel filter housing lid deformed where someone has pushed it into the fuel filter without care and pinched the the O'ring out/off of its seal!

My theory is that around town the fuel flow through the filter isn't that great and fluctuates so it's ok but following a steady 70-80mph M/way drive the fuel flow would be steady and flowing at a high rate, thus when pulling up to a round about or lights and eng speed dropped mixed with that O'ring not sealing the fuel flow back to the tank partially sucks/emptys the fuel filter causing negative pressure and cause an air lock type symptom making the engine cut out.

I think the cranking of the eng & allowing the engine to sit for 5-10mins allows the fuel to be drawn back up from the tank thus reversing the effect!

Your thoughts please guys!!??

Once again thank you Greg.

Hi,

Thanks for this. Had a fortnight calling out the RAC 3 times to recover me after 1+ hours driving on the motorway at a steady 70mph and then having the car stall on the exit slip roads. The car starts first time in the morning and gets me the 10 miles each way journey to work. Before seeing your post, the garage I use had spent several hours trying to repeat the failure (no flags on the EMU) and eventually got a couple of seconds of 'glitch' on the telemetry. They replaced the oil pressure regulator (Ford wanted £1200 for the part, but the garage sourced and fitted one for £200). I took the car for a test run on the M4 this weekend and it stalled as I left junction 32! Then I found your post and suggested to the garage they check the seal on the fuel filter that had been fitted in a major service 3 weeks ago. Sure enough, the O ring was damaged and not sealing the filter. Had it replaced yesterday (assured now that it is a tight fit), so 'looking forward' to a test drive this weekend. The owner of the garage did, at my suggestion, take the car out yesterday for a good run up and down the M50 and did not encounter any problems. The garage is excellent - we have been using them for years - and their efforts to resolve the problem have so far been excellent.

I'd be VERY surprised if the fuel filter seal replacement doesn't fix your issue, going on the symptoms you've described.  Also make sure the "collar" that holds the seal and housing lid in place in nice and tight because the tiniest bit of air getting in can and likely will cause problems.  The collar came slightly loose on mine and after 1 hour on the M1 the engine cut out on a slip road in rush hour traffic .  The root cause was simply that the collar had worked loose enough that it wasn't applying enough downward pressure on the seal and it had clearly been letting a small amount of air into the filter housing.  Tightened it up and 3 months later not had any problems.

Don't forget to post back in a couple of weeks etc to let us all know if it's actually fixed.

Similar topic with earlier o-ring tip.

Interesting video with lesson learned: