2007 focus 1.8 tdci misfire.

[Dan79]

Hi there, I'm new to this. Just purchased a 2007 focus 1.8 tdci. Runs quite rough like it's running on 3 cylinders. I've replaced the air filter and put a can of egr valve cleaner through it. I've also ordered a new fuel filter. Looks like it's been sitting for a while. Any ideas of what it could be? Could it be a blocked injector? 

[Joss max]

Hello and welcome Dan

Any codes showing ? You should get it read for fault codes to start with. That then gives an idea where to start looking. get that done then let us know what has shown up.

Take things from there

[Tdci-Peter]

14 hours ago, Dan79 said:

Runs quite rough like it's running on 3 cylinders.

Hi,

Like Joss says, error codes (DTCs) in the engine would be useful. There can be codes present without the EML (the engine management warning light) being on. Most electrical, and major mechanical faults will generate DTCs.

Does the rough running extend right up the power & rev range, or is it mainly at idle? Injector problems usually affect most of the range.

Blanking off the EGR (a few quid off Ebay) can be used to diagnose / eliminate EGR problems. It does not usually cause an error code on these engines.

Badly clogged fuel filter is a possible. But starting these engines after a filter change is hard. They have no tank mounted pump, and any air on the main pump inlet will prevent starting. I fitted a non-return valve in the supply to the filter, and used a priming pump, to fill the filter and fill the filter outlet pipe. It started and ran ok on the second attempt, with no more than the usual cranking time, with that method.

These engines are less complex than some, but there are still quite a few possibilities: MAF & MAP sensors, Air & CH temperature sensors, Diesel pump & its regulation system, Injector, wiring.

For diagnostics, ignoring garages at up to £100 a go, there are two options:

1) Get a generic OBD2 scanner. From about £10.00. I got a U480 off eBay, worked fine. Very easy to use, self contained, but limited capabilities. OR

2) Get Forscan. It is not quite as simple as the self contained OBD2 scanner, but much more comprehensive.

Forscan is a powerful Ford specific system, Cost £15.00 for the interface. Needs a computer of some sort. (COM port, USB, bluetooth or WiFi interfaces available). You will find a lot about ELM327 & Forscan on this site, which together provide a very comprehensive diagnosis & maintenance tool. James (jeebowhite) has done a nice guide:
http://www.fordownersclub.com/forums/applications/core/interface/file/attachment.php?id=21196

Reply here if interested in the Forscan route. It can monitor sensor readings like fuel rail pressure, MAF & MAP readings, so can help narrow down the possibilities, as well as reading far more DTCs than a generic scanner.

[Dan79]

Thank you for the advice. I've cleaned the egr valve and had injectors tested with no faults showing. Been told its the flywheel and clutch. Just have to book in to get done at a hefty price.

[Tdci-Peter]

3 hours ago, Dan79 said:

Been told its the flywheel and clutch. Just have to book in to get done at a hefty price.

DMF is a possible cause. But there is usually quite a bit of noise (rattling, clanking) when this goes. Appreciable vibration on the clutch pedal is also normally a symptom. Make sure the diagnosis you have is either from a very trustable source, or confirmed by a 2nd opinion before committing to this.

It would be expensive to have it done on suspicion, and find it was not the cause.

[Biigfella]

I am having the same issue. 06 focus. First i tried injector cleaner, nothing. Changed all filters and still nothing. An injector specialist told me the injectors are fine, and its an electronic problem. No fault codes appear on 3 different computer tests. I am really stumped. It rrally judders hard especially wheb going uphill. Can anybody suggest anything? One auto elec told me its the abs sensor playing up but i doubt that

[Tdci-Peter]

On 8/31/2020 at 10:44 AM, Biigfella said:

It really judders hard especially wheb going uphill. Can anybody suggest anything? One auto elec told me its the abs sensor playing up but i doubt that

My car judders badly going up steep hills in lower gears, when the road is poor and bumpy. It can really shake, but definitely linked to bumps or variations in the road surface. On a good surface, or in 4th or 5th gear, it is fine at full throttle.

This road dependant judder could be an over-active ABS (or ESP), over compensating for a bit of wheelspin on a bump, or it could be a worn front suspension bush, most likely the wishbone. It has always done it a bit, but does seem to be getting slightly more prone to it. I cure it by easing off on the throttle a bit on surfaces I know are poor.

If the judder happens in all gears, or on perfect road surfaces, then injectors, DMF & engine mounts are a few items that spring to my mind.

[Deerstones]

I have a 2008 with the same issue, it only has 16k on the clock and has done this since 2013,  Ford diagnosed a faulty injector and injector seals and carried out the work charging £600 as a new injector was fitted, it didn't cure it.     Wondering if another or all the seals need replacing....