Hi all

I have a 2009 1.8TDCI Focus, 50k (miles) on the clock.

Bit of a story to this, please bear with me.

About 18 months ago, it threw up the Engine Malfunction light - judders whilst driving (misfires), with eventual failure and subsequent limp-home mode. Being a total noob, I simply replaced the fuel filter and the problem seemed to go away. Job done, or so I thought.

6 Months later, it came back. And as quickly as it had come back, it disappeared.

It was due it's service (all services done at Ford dealers), so I asked the Ford tech to have a look, give me an opinion. He reliably informed me that it was one of the injectors was faulty and (paraphrasing) "if you replace one, you should replace them all". That would have set me back 1500Euro just for the parts, never mind the labour. He was also able to tell me that if it happened, to pull in, give it 10-15 minutes off and then go again.

Didn't change the injector - thanks to my brother's advice. Instead, took it back off them and kept driving. No further problems until about 6 weeks ago - 1 day it started juddering every so often and then the engine malfunction and limp-home mode.

Since the last service, I had bought an ELM327 cable (with the HS-CAN switch) and had ForScan installed on my laptop. I had this with me and was able to tell that it was a P0201 error - Injector Open Circuit.

Through yet another relative, I arranged for this injector to be replaced with a Ford-supplied injector and re-coded by a Ford tech (not my local garage).

On a related note, this guy commented that in all his years of changing injectors on Focus's (Focii?), it was only ever Injector 1 that gave trouble.

So this loosened 400 bills from my wallet and I thought, ok money well spent. Got it back 2 weeks ago, and with the exception of 1 minor judder, all was going well. Until today.

Now, the blasted thing reports Injector 4 is open circuit. Injector 4 never gave a problem before and now it's causing the problem.

My brother (a dab hand with his motorbike engines) reckons it could be an electrical problem and that if an injector goes, it's gone. No resurrections. This makes sense. Why would it just start working again.

Can I please have your suggestions on potential causes and possible remedies.

I read in the Frequent problems list that Fuel Filter changes are a good idea - is twice a year overkill? (I do less than 10000 miles per year anyway, so it's not like I'm keeping the Diesel Fuel business going)

I'm disinclined to replace Injector #4 - problems don't jump from 1 injector to the next.

Thanks for taking the time to read this.

Sc27

Hi there. Sounds like a wiring issue to me. With your mileage i wouldnt be expecting fuel injectors to fail. Im on 132k and im just starting to get ticking injectors..

Definitely have a good look at the wiring and the connections to the injector, making sure theyre fully seated and theres no corrosion inside. Also have a look at where it goes over the rocker cover and make sure its properly insulated. It could be heating up causing issues to the wires if not insulated properly.

Also you might want to throw in a camshaft positon sensor to see if that fixes your other juddering issue. Its the light blue/grey type sensor that is on the top of the engine that sits next to the injector wirings.

Id also change the fuel filter every year as its good preventitive maintenance

Nexus

Thanks for the suggestions and info - 132k sounds a bit more like it.

I've had the injector connections apart - seems ok: weather sealing is good, cables mostly not under any strain, no visible signs of any damage. On the cabling, I've only had a very quick look so far - haven't started to separate them in the loom. I'll have a better look as soon as I can.

Do you think that the juddering could be unrelated to the alleged injector misfires? I had associated the two because the judders would always precede the EML coming on, but I note that they don't always mean that it's going to happen - sometimes there'll be a judder and nothing is recorded in the ECU.

Cheers

Sc27

What is the part number on each of the injectors? they should be Siemens injectors with 4M5Q-9F593-AD ADQTL as the code for the focus.

What is the part number on each of the injectors? they should be Siemens injectors with 4M5Q-9F593-AD ADQTL as the code for the focus.

@Nexus

Sorry for the delay in replying - tonsil deep in work and haven't gotten near her in some time.

I haven't taken out the 3 originals (2, 3, 4). The new one that was fitted was a Ford-provided unit, so I'd be expecting it to be right.

A quick update on this:

I've changed the fuel and air filters since I posted on here. The fuel filter was a bit dirty, but certainly not bogged down with crap. Bit of wax in the bottom, but only a tiny amount - would just about cover a postage stamp if spread out.

The air filter was a bit dirty too, but again, not exactly filled with rubbish.

I've also had a look at the Camshaft Position sensor - taken it out and reseated it. I'll order one of these anyway, just in case.

I've driven her a bit since and despite one or two very minor judders, she has been fine. Only issue is that I haven't really taken her that far away - bit reluctant in case she breaks down on me.

On the electrical end of things, I'm planning to have a good long look at the wiring loom in the near future as some of the cable ties that hold it in place (on the way down to the ECU) appear to have been cut and I'm wondering now if there's a possibility that cables are rubbing against each other/anything else. Any experience of this kind of thing? Anyone ever replace their wiring loom?

Thanks again

Sc27

Buy a can of BG244K , superb cleaner for the fuel system and helps the injectors spray and not squirt . :D

@Andy (and everyone else) - do you reckon that additives like BG244 work or have you used it and found good results? I've often wondered if it isn't just snake oil with a different badge.

Jacking her up tomorrow for a look around (weather permitting).

Out of interest, does anyone know if there's a knack to disconnecting the wiring loom at the junction that's just above the engine underneath the wiper gutter (there's probably a better name for this but I don't know it yet).

Ta

scuttle panel is the words your looking for. As for the bg244k It's not a gimmick it really is good stuff, one can very 7-10000 miles, Thousands of people use it (for diesels) of BG44K for petrol and diesels ....

Andy

Thanks for the reply. I have a can on order.

I'm also looking at doing an EGR blanking - no sense in pumping dirty air back into the system that I'm trying to ensure is clean.